Should covid be left to spread among the young and healthy?

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As new waves of covid-19 sweep the world, lockdowns are back in fashion. This time, though, they are a harder sell. They certainly save lives. But it is now clear that the lost jobs, the disruption to education and medical services, and the harm to mental health that they cause all exact tolls of their own—and these are paid not just in misery, but in deaths. Systems of “test and trace”, intended to stop those exposed to the virus from passing it on, seem to have worked in some places, but not in others.

In the absence of a vaccine, or of effective drug treatments, the question of how much longer this can go on for is thus being asked more insistently. And on October 4th a trio of public-health experts from Harvard, Oxford and Stanford universities put out a petition calling on governments to change course in a radical way.

The Great Barrington Declaration, named after the town in Massachusetts where it was signed, proposes that the contagion be allowed to spread freely among younger and healthier people while measures are taken to protect the most vulnerable from infection. This approach rests on the concept of “herd immunity”, whereby the disease would stop spreading when a sufficient share of the population had become immune as a result of infection.

Thesis

That is a controversial idea. And on October 14th another group of health experts published a rebuttal in the Lancet, calling the declaration “a dangerous fallacy unsupported by scientific evidence”. Their letter has a grand title, too: the John Snow Memorandum, named after an Englishman who established the principles of epidemiology in the 1850s. It urges governments to do whatever it takes to suppress the spread of sars-cov-2, the coronavirus that causes the illness. In particular, it calls for continuing restrictions until governments fix their systems to test, trace and isolate infected people. Online, the duelling petitions have each gathered thousands of signatures from scientists around the world.

The Great Barrington proposal is a risky one. Any judgment about whether natural infection can create herd immunity to sars-cov-2 is premature. It has not yet been established whether infected people develop durable immunity against reinfection—and if so, how common that immunity might be. Few cases of reinfection have yet been confirmed conclusively. (This is done by establishing that the genomes of the virus particles found the first and second times around are indeed different, meaning the second infection cannot be a continuation of the first.) Lots of reinfections could, though, be happening undetected. About 80% of those infected with sars-cov-2 have mild symptoms, or none at all. The vast majority of these mild cases are not getting tested, even in countries with ample testing capacity.

The ideal study to settle this uncertainty would involve retesting frequently a large cohort of people known to have been infected in the past, to see how many become infected again. But identifying those who have had mild or symptom-free infection is hard. Tests that look for antibodies against sars-cov-2 in big surveillance studies often fail to detect those antibodies in mild cases. Some studies have found that antibodies in these patients wane over time. But whether that equates to waning immunity is still unknown.

If the immune response to sars-cov-2 is anything like that to the other six coronaviruses which infect human beings, letting it spread would eventually slow transmission down—for a period. The question is how long that period would be. Four of the six cause symptoms described as “the common cold” (though other types of viruses cause colds as well). Infection with these confers protection that typically lasts for less than a year. The other two human coronaviruses, sars and mers, cause serious illness. Immunity to these is estimated to last for several years. If protection in the case of sars-cov-2 is short-lived or not particularly strong, the virus will keep surging in recurrent epidemic waves, much as happens each winter with other respiratory bugs. If it is longer-lived, the Great Barrington argument is more plausible.

Antithesis

The authors of the John Snow memorandum argue, though, that deaths and disability under the Great Barrington plan would be huge, even if the herd-immunity gamble is on the money. The share of the population which would need to be infected depends on how easily sars-cov-2 spreads. In its simplest form, the herd immunity threshold as a fraction of the population is 1-(1/r), where r is the average number of people who catch the virus from an infected person. With no social distancing, the r values for Europe are in the range of 3-4, meaning that herd immunity would kick in when two-thirds to three-quarters of people have been infected (see chart 1). This formula, though, assumes everyone has the same chance of infection, which is not the case in reality. If chances of infection vary, then the threshold is lower than the formula suggests. And this may matter. Young people, for example, have more contacts than oldsters, and are thus more likely to pick the virus up. Some models which assume plausible variety in contact rates have concluded that the herd-immunity threshold in western Europe could therefore be as low as 43%.

It is also possible that this threshold has been lowered by pre-existing immunity conferred by past infections with cold-causing coronaviruses. That sort of protection would come from memory t-cells, another part of the immune system’s armamentarium. Unlike antibodies, which are custom-made to attack a given pathogen, t-cells are less picky in recognising and going after a harmful invader. Several studies of blood samples taken before sars-cov-2 emerged have found t-cells that put up a robust reaction to that virus in 20-50% of cases. This is an exciting result. But it is not yet known whether people with such t-cells will have less severe covid-19 disease, or none at all, if they are exposed to sars-cov-2 in real life. An outbreak of covid-19 on a French aircraft-carrier did not come to a halt until 70% of the crew had become infected, which suggests that cross-protection from common-cold infections may just be a nice theory.

All this means that if sars-cov-2 is left on the loose perhaps half or more of people will become infected over the course of six months. The Great Barrington proposal is that, as this happens, countries must double down on protecting the most vulnerable. Identifying who these vulnerable people are is not a foolproof task, but knowledge about the worst combinations of risk factors is getting better. A paper published in the BMJ on October 20th describes a covid-19 risk calculator that predicts an individual’s probability of hospitalisation and death, using data on 6m people in Britain. Validation of this algorithm on 2m others showed that the 5% of people predicted to be at greatest risk by the calculator accounted for 75% of the covid-19 deaths.

But awareness of such risk scores or simpler markers of high risk (old age, obesity and diabetes in particular) is all too often of little use in practice. Most people cannot change their lives in ways that eliminate their risk of infection, particularly when there are lots of infections all around. Those who care for them, or live in the same home, would get infected at some point—and unwittingly pass the virus on. Though most deaths from covid-19 are among the elderly, many adults in younger age groups are at high risk. At the peak of the covid-19 epidemic in England and Wales deaths among people aged 45 to 64 years were 80% higher than usual (see chart 2) despite a lockdown and official advice to the most vulnerable to “shield” from the virus by not leaving their homes at all.

Although the vast majority of people do not get seriously ill if covid strikes, as many as 5% of those who develop symptoms may remain unwell for at least eight weeks (a condition known as “long covid”). Some of them have not recovered after six months, and there are fears that they may never get back to normal. Even if less than 1% of the infected end up in this unlucky group, for a country the size of Britain that would be hundreds of thousands of people with lifelong disability. Another big unknown is whether there are any hidden health consequences of the virus that may show up in the future. Some studies have found subtle heart changes following mild covid-19. It may not be clear for years whether these lead to serious heart problems for some people, or do not matter at all.

Synthesis?

The Great Barrington plan, then, is a high-risk, high-reward proposition. The John Snow one, by contrast, would minimise covid deaths in the short term, but lives lost in the long-term, because of lockdowns and other disruptions, might end up being more numerous. Over time, as governments fix the test and trace systems that are needed to replace the broader restrictions, the motivation for the Great Barrington course of action will become less potent.

With luck, this whole debate will be rendered irrelevant by the invention of a vaccine or the development of suitable drugs to treat covid. The results of several efficacy trials of vaccines, and tests on promising pharmaceuticals, are expected in the coming weeks. If covid-19 is less deadly and some herd immunity comes from a vaccine, the paths charted by the two petitions will, eventually, come together. 

Your Coronavirus Test Is Positive. Maybe It Shouldn’t Be.

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Some of the nation’s leading public health experts are raising a new concern in the endless debate over coronavirus testing in the United States: The standard tests are diagnosing huge numbers of people who may be carrying relatively insignificant amounts of the virus.

Most of these people are not likely to be contagious, and identifying them may contribute to bottlenecks that prevent those who are contagious from being found in time. But researchers say the solution is not to test less, or to skip testing people without symptoms, as recently suggested by the Centers for Disease Control and Prevention.

Instead, new data underscore the need for more widespread use of rapid tests, even if they are less sensitive.

“The decision not to test asymptomatic people is just really backward,” said Dr. Michael Mina, an epidemiologist at the Harvard T.H. Chan School of Public Health, referring to the C.D.C. recommendation.

“In fact, we should be ramping up testing of all different people,” he said, “but we have to do it through whole different mechanisms.”

In what may be a step in this direction, the Trump administration announced on Thursday that it would purchase 150 million rapid tests.

The most widely used diagnostic test for the new coronavirus, called a PCR test, provides a simple yes-no answer to the question of whether a patient is infected.

But similar PCR tests for other viruses do offer some sense of how contagious an infected patient may be: The results may include a rough estimate of the amount of virus in the patient’s body.

“We’ve been using one type of data for everything, and that is just plus or minus — that’s all,” Dr. Mina said. “We’re using that for clinical diagnostics, for public health, for policy decision-making.”

But yes-no isn’t good enough, he added. It’s the amount of virus that should dictate the infected patient’s next steps. “It’s really irresponsible, I think, to forgo the recognition that this is a quantitative issue,” Dr. Mina said.

The PCR test amplifies genetic matter from the virus in cycles; the fewer cycles required, the greater the amount of virus, or viral load, in the sample. The greater the viral load, the more likely the patient is to be contagious.

This number of amplification cycles needed to find the virus, called the cycle threshold, is never included in the results sent to doctors and coronavirus patients, although it could tell them how infectious the patients are.

In three sets of testing data that include cycle thresholds, compiled by officials in Massachusetts, New York and Nevada, up to 90 percent of people testing positive carried barely any virus, a review by The Times found.

On Thursday, the United States recorded 45,604 new coronavirus cases, according to a database maintained by The Times. If the rates of contagiousness in Massachusetts and New York were to apply nationwide, then perhaps only 4,500 of those people may actually need to isolate and submit to contact tracing.

One solution would be to adjust the cycle threshold used now to decide that a patient is infected. Most tests set the limit at 40, a few at 37. This means that you are positive for the coronavirus if the test process required up to 40 cycles, or 37, to detect the virus.

Tests with thresholds so high may detect not just live virus but also genetic fragments, leftovers from infection that pose no particular risk — akin to finding a hair in a room long after a person has left, Dr. Mina said.

Any test with a cycle threshold above 35 is too sensitive, agreed Juliet Morrison, a virologist at the University of California, Riverside. “I’m shocked that people would think that 40 could represent a positive,” she said.CORONAVIRUS SCHOOLS BRIEFING: The pandemic is upending education. Get the latest news and tips as students go back to school.Sign Up

A more reasonable cutoff would be 30 to 35, she added. Dr. Mina said he would set the figure at 30, or even less. Those changes would mean the amount of genetic material in a patient’s sample would have to be 100-fold to 1,000-fold that of the current standard for the test to return a positive result — at least, one worth acting on.

The Food and Drug Administration said in an emailed statement that it does not specify the cycle threshold ranges used to determine who is positive, and that “commercial manufacturers and laboratories set their own.”

The Centers for Disease Control and Prevention said it is examining the use of cycle threshold measures “for policy decisions.” The agency said it would need to collaborate with the F.D.A. and with device manufacturers to ensure the measures “can be used properly and with assurance that we know what they mean.”

The C.D.C.’s own calculations suggest that it is extremely difficult to detect any live virus in a sample above a threshold of 33 cycles. Officials at some state labs said the C.D.C. had not asked them to note threshold values or to share them with contact-tracing organizations.

For example, North Carolina’s state lab uses the Thermo Fisher coronavirus test, which automatically classifies results based on a cutoff of 37 cycles. A spokeswoman for the lab said testers did not have access to the precise numbers.

This amounts to an enormous missed opportunity to learn more about the disease, some experts said.

“It’s just kind of mind-blowing to me that people are not recording the C.T. values from all these tests — that they’re just returning a positive or a negative,” said Angela Rasmussen, a virologist at Columbia University in New York.

“It would be useful information to know if somebody’s positive, whether they have a high viral load or a low viral load,” she added.The Coronavirus Outbreak ›

Officials at the Wadsworth Center, New York’s state lab, have access to C.T. values from tests they have processed, and analyzed their numbers at The Times’s request. In July, the lab identified 794 positive tests, based on a threshold of 40 cycles.

With a cutoff of 35, about half of those tests would no longer qualify as positive. About 70 percent would no longer be judged positive if the cycles were limited to 30.

In Massachusetts, from 85 to 90 percent of people who tested positive in July with a cycle threshold of 40 would have been deemed negative if the threshold were 30 cycles, Dr. Mina said. “I would say that none of those people should be contact-traced, not one,” he said.

Other experts informed of these numbers were stunned.

“I’m really shocked that it could be that high — the proportion of people with high C.T. value results,” said Dr. Ashish Jha, director of the Harvard Global Health Institute. “Boy, does it really change the way we need to be thinking about testing.”

Dr. Jha said he had thought of the PCR test as a problem because it cannot scale to the volume, frequency or speed of tests needed. “But what I am realizing is that a really substantial part of the problem is that we’re not even testing the people who we need to be testing,” he said.

The number of people with positive results who aren’t infectious is particularly concerning, said Scott Becker, executive director of the Association of Public Health Laboratories. “That worries me a lot, just because it’s so high,” he said, adding that the organization intended to meet with Dr. Mina to discuss the issue.

The F.D.A. noted that people may have a low viral load when they are newly infected. A test with less sensitivity would miss these infections.

But that problem is easily solved, Dr. Mina said: “Test them again, six hours later or 15 hours later or whatever,” he said. A rapid test would find these patients quickly, even if it were less sensitive, because their viral loads would quickly rise.

PCR tests still have a role, he and other experts said. For example, their sensitivity is an asset when identifying newly infected people to enroll in clinical trials of drugs.

But with 20 percent or more of people testing positive for the virus in some parts of the country, Dr. Mina and other researchers are questioning the use of PCR tests as a frontline diagnostic tool.

People infected with the virus are most infectious from a day or two before symptoms appear till about five days after. But at the current testing rates, “you’re not going to be doing it frequently enough to have any chance of really capturing somebody in that window,” Dr. Mina added.

Highly sensitive PCR tests seemed like the best option for tracking the coronavirus at the start of the pandemic. But for the outbreaks raging now, he said, what’s needed are coronavirus tests that are fast, cheap and abundant enough to frequently test everyone who needs it — even if the tests are less sensitive.

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“It might not catch every last one of the transmitting people, but it sure will catch the most transmissible people, including the superspreaders,” Dr. Mina said. “That alone would drive epidemics practically to zero.”

One Meeting in Boston Seeded Tens of Thousands of Infections, Study Finds

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On Feb. 26, 175 executives at the biotech company Biogen gathered at a Boston hotel for the first night of a conference. At the time, the coronavirus seemed a faraway problem, limited mostly to China.

But the virus was right there at the conference, spreading from person to person. A new study suggests that the meeting turned into a superspreading event, seeding infections that would affect tens of thousands of people across the United States and in countries as far as Singapore and Australia.

The study, which the authors posted online on Tuesday and has not yet been published in a scientific journal, gives an unprecedented look at how far the coronavirus can spread given the right opportunities.

“It’s a really valuable study,” said Dr. Joshua Schiffer, a physician and mathematical modeling expert who studies infectious diseases at the Fred Hutchinson Cancer Research Center in Seattle and was not involved in the research.

Dr. Schiffer said that the new genetic evidence fit well with what epidemiologists and disease modelers have been learning about the coronavirus. The Biogen conference, he said, was just one of many similar events that amplified and spread the virus in its early months. “I don’t think it’s a fluke at all,” he said.

The results came out of a project that began in early March at the Broad Institute of Harvard and M.I.T., a research center specializing in large-scale genome sequencing. As a wave of Covid-19 patients crashed into Massachusetts General Hospital, the Broad researchers analyzed the genetic material of the viruses infecting the patients’ cells. The scientists also looked at samples from the Massachusetts Department of Public Health, which ran tests around Boston at homeless shelters and nursing homes. All told, the scientists analyzed the viral genomes of 772 people with Covid-19 between January and May.

The researchers then compared all of these genomes to trace where each virus came from. When a virus replicates, its descendants inherit its genetic material. If a random mutation pops up in one of its genes, it will also get passed down to later descendants. The vast majority of such mutations don’t change how the virus behaves. But researchers can use them to track the spread of an epidemic.

“It’s kind of like a fingerprint we can use to follow viruses around,” said Bronwyn MacInnis, a genomic epidemiologist at the Broad Institute.

The first confirmed case of the coronavirus in Boston turned up on Jan. 29. The patient had traveled from Wuhan, China, and his virus carried distinctive mutations found in Wuhan. But Dr. MacInnis and her colleagues didn’t find any other viruses in Boston from later months with the same genetic fingerprint. It’s likely that the patient’s isolation prevented the virus from spreading.

But as February rolled on, the researchers determined, at least 80 other people arrived in Boston with the virus. Undiagnosed, they spread it to others.

Most of the viral lineages in Boston have a genetic fingerprint linking them to earlier cases in Europe, the study found. Some travelers brought the virus directly from Europe in February and March, whereas others may have picked up the European lineage elsewhere in the northeastern United States.

Dr. MacInnis and her colleagues took a detailed look at a few key places to see how the virus swept through the city. At Massachusetts General Hospital, for example, they found that coronaviruses in patients did not share many of the same mutations. That was a relief, because it meant that the hospital was not a breeding ground where a single virus could spread quickly from patient to patient.CORONAVIRUS SCHOOLS BRIEFING: The pandemic is upending education. Get the latest news and tips as students go back to school.Sign Up

But that’s exactly what happened in a skilled nursing home where 85 percent of patients and 37 percent of the staff were infected. The researchers identified three different virus lineages in the home, but one of them accounted for 90 percent of the infections.

Such superspreading events are a hallmark of the coronavirus. When an infected person shows up in the right place — generally inside, with poor ventilation and close contact with other people — the virus can infect a lot of people in very little time. These unfortunate events don’t happen often, and so most people who get infected with the coronavirus don’t pass it on to anyone else.

The virus that raged through the nursing home didn’t spread beyond its walls, as far as Dr. MacInnis and her colleagues could tell. But when the virus showed up at the Biogen conference, the story turned out very differently.

The researchers were able to sequence 28 viral genomes from people at the meeting. All of them shared the same mutation, called C2416T. The only known samples with that mutation from before the Biogen event came from two people in France on Feb. 29.The Coronavirus Outbreak ›

It’s possible that a single person came to the meeting from Europe carrying the C2416T mutation. It’s also possible that the virus carrying this mutation had already been in Boston for a week or two, and someone brought it into the meeting.

As the attendees spent hours together in close quarters, in poorly ventilated rooms, without wearing masks, the virus thrived. While replicating inside the cells of one meeting attendee, the virus gained a second mutation, called G26233T. Everyone who was subsequently infected by that person carried the double-mutant virus.

From the meeting, the researchers concluded, this lineage spread into the surrounding community. In a Boston homeless shelter, for example, researchers found 51 viral samples with the C2416T mutation, and 54 with both mutations.

“We had no idea it would be associated with the conference,” Dr. MacInnis said. “It came as a complete surprise.”

The researchers estimated that roughly 20,000 people in the Boston area could have acquired the conference virus.

New York saw a similar pattern, according to Matthew Maurano, a computational biologist at N.Y.U. Langone Health. After many viral strains arrived from Europe in February, a few came to dominate the city. “A lot of lineages die off, and some spread enormously,” Dr. Maurano said.

The Boston double-mutant spread particularly far. Researchers identified this lineage in samples collected later in Virginia, North Carolina and Michigan. Overseas, it turned up in Europe, Asia and Australia.

Dr. Jacob Lemieux, a co-author of the new study and an infectious disease physician at Massachusetts General Hospital, said it was impossible at the moment to determine how many people acquired the virus in the months after the Biogen conference. But it would be in the tens of thousands.

Six months after the conference, Dr. MacInnis said that it should serve as a warning to anyone who thinks life can return to an unmasked version of normal before the virus is brought under control.

“One bad decision can affect a lot of people,” she said. “And the ones who suffer the most from that reality are the most vulnerable among us.”

When covid-19 becomes a chronic illness

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The symptoms began in March, says Laura, a British woman in her mid-20s. At first covid-19 felt like a bad case of flu: a dry cough, fever, shortness of breath, loss of smell, “horrendous nausea” and general fatigue. After three weeks of rest, things started to improve. Five months later, she has still not recovered. Sometimes her symptoms ease for a week or two, but they inevitably return. “When it’s bad I can’t even go on work calls, because if I talk too much I can’t breathe.”

In March, as covid-19 cases began their exponential rise in country after country, doctors focused on saving patients’ lives. Speedy sharing of knowledge, clinical trials and hands-on experience have made the illness less deadly. In Britain about half the patients treated in intensive-care units (icus) in the weeks to the middle of April died. By the end of June mortality was below 30%. Reductions were seen across all age groups, which means the fall cannot have been caused by fewer frail old people arriving in hospital (see chart 1). In places where the epidemic has subsided, calmer wards have meant better care. But improved knowledge about treatment probably accounts for much of the improvement.

Doctors have learned a lot. They have stopped rushing covid-19 patients onto ventilators, which can cause lung damage. Oxygen supplied through small prongs in the nostrils is much less invasive and often does the job. In British icus the share of covid-19 patients on ventilation fell from 90% in the early days to 30% in June. Treatment protocols have improved further with the addition of dexamethasone, an immune-dampening drug that increases survival rates in patients who need oxygen.

Now, though, doctors and scientists are shifting their focus to those who survive the infection—including the subset of people like Laura, who have never been ill enough to be hospitalised, but who have also never recovered sufficiently to return to normal life.

In most people, covid-19 is a brief, mild illness. Between a third and a half of those infected do not notice any symptoms. In those who do become unwell symptoms usually clear within two to three weeks with just home rest. In Europe only around 3-4% of those who become infected are admitted to hospital.

Yet at the same time it is becoming clear that some small but significant proportion of those infected have symptoms that persist for months. Prolonged recovery is not unusual for patients hospitalised for pneumonia, a frequent complication of covid-19. It is also common for people who have been admitted to an icu, who are by definition seriously ill. But many clinicians say that the share of covid-19 patients with lingering problems is far higher than is seen with other viral illnesses such as influenza. The problems are also more varied, often including lung, heart and psychological symptoms, says Sally Singh of the University of Leicester, who leads the development of a covid-19 rehabilitation programme for Britain’s health service.

The walking wounded

Anecdotal reports of long-lasting illness have been around since the early days of the pandemic. But with more than 22m cases confirmed worldwide, and with infection rates having peaked several months ago in most rich countries, statistical patterns about the virus’s lingering effects are starting to emerge. A paper in the British Medical Journal on August 11th concluded that as many as 60,000 people in Britain have long-term symptoms. Yet only about 6% of Britain’s population—around 4m people—seems to have been infected with the virus so far.

Severity of the illness is one predictor of lasting problems. Ian Hall, the director of the Biomedical Research Centre at the University of Nottingham, reckons that 30-50% of patients hospitalised with covid-19 have significant symptoms six to eight weeks after they have been discharged. That number rises further for patients who were admitted to an icu. But even those who escaped with a mild illness, like Laura, are at risk. More than 10% of them remain unwell for more than three weeks, according to a patient-tracking study that follows mostly American and British patients. They struggle with fatigue, breathlessness, body aches and cognitive problems which many describe as “brain fog” (see chart 2).

Some long-term covid-19 patients may be suffering from undiagnosed conditions such as diabetes or thyroid dysfunction, which are “unmasked” by the infection, says Avindra Nath of the National Institutes of Health in America. For others, the collection of symptoms is suggestively similar to those seen in chronic fatigue syndrome (cfs). The biological causes of cfs are still poorly understood, but data from America indicate that three-quarters of cases follow viral or bacterial infections. One hypothesis is that the syndrome is caused by the immune system failing to properly stand down after being called on to battle an infection. It may be that sars-cov2, the virus that causes covid-19, is unusually likely to provoke such a lingering over-reaction.

If the root cause is not known, then the growing understanding of just what covid-19 can do to the body can at least suggest what sorts of care long-term sufferers may need. The hallmark of many covid-19 cases is damage to the lungs. Aggressive inflammation leads to the destruction of lung tissue and the formation of scars. The scarring, in turn, impedes the flow of oxygen from the lungs into the blood. That can cause breathlessness, even with light exercise. Small studies of covid-19 patients discharged from hospitals have found that 25-30% have impaired oxygen flow.

The prognosis is unclear. People treated in icus for other viral infections usually recover about 80% of their previous lung function fairly quickly, but the final 20% can take three to six months, says Dr Hall. And in some cases lung scarring can worsen over time, especially if combined with new health problems later in life.

Breathing problems can also arise from another effect of covid-19—its tendency to cause blood clots, which is unusual for a respiratory virus. When they form in the lungs, clots can choke off blood flow, making it even harder to absorb oxygen. And the virus may cause breathlessness in a more subtle way, too, by damaging the lining of blood vessels, which limits how much blood can flow through them.

Covid-19 can also damage the heart. It can inflame the tissues that surround the organ, as well as the blood vessels that ferry nutrients to it. That can weaken the heart muscle, and eventually lead to heart failure. Blood clots cause problems here, as well, since the heart must pump harder to push blood through partly blocked vessels. Over time, that can weaken the muscle.

Nobody knows exactly how often such cardiac complications occur. But news from Germany is worrying, says Clyde Yancy, a cardiologist at Northwestern University, in Illinois. Using mri scans, one study found evidence that covid-19 causes inflammation and other heart changes—including in people who had tested positive for the virus more than two months earlier and were, by the time of their scans, free from symptoms. The changes were small, and not enough by themselves to cause clinical symptoms. But even a minor injury to the heart may eventually lead to heart failure if it lingers for long enough, says Dr Yancy.

Least understood are the long-term effects of covid-19 on the nervous system and the brain. Patients with lingering post-covid symptoms complain of headaches, tingling and numbness in the feet, and other neurological problems. Problems that suggest a dysfunction of the autonomic nervous system, such as irregular heart beat, dry mouth and gastrointestinal problems are also common, says Dr Nath. But the exact cause of such symptoms remains unclear, as does the reason why more than half of those infected suffer a temporary loss of their sense of smell. (Some, rather than losing it, have it altered instead, so that things smell different after the infection than they did beforehand.)

Confronted with a baffling array of symptoms and few detailed explanations about exactly what is going wrong, doctors are desperate for guidance. A third of general practitioners in Britain already have patients with lasting post-covid symptoms. For now, the best they can offer is referral to lung or cardiac rehabilitation. Such therapy may improve a patient’s quality of life with something as simple as a breathing exercise. Britain, Belgium and other countries are setting up specialised covid-19 rehabilitation programmes for those recovering from the disease. Waiting lists are already long.

In the absence of understanding, doctors must fall back on lessons from other illnesses. Lingering symptoms are not the exclusive preserve of covid-19. Full recovery from other viral diseases such as influenza can occasionally take months. Data on cfs suggests chances of recovery are best in the first three months.

More specific data are on the way. Studies in America, Britain, China and Europe have enrolled thousands of patients, and should begin reporting initial results in the next few months. But for now, those suffering the lingering effects of the disease must deal not only with the physical symptoms, but with uncertainty about just how long it will take them to get better. ■

The Plan That Could Give Us Our Lives Back

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mina is a professor of epidemiology at Harvard, where he studies the diagnostic testing of infectious diseases. He has watched, with disgust and disbelief, as the United States has struggled for months to obtain enough tests to fight the coronavirus. In January, he assured a newspaper reporter that he had “absolute faith” in the ability of the Centers for Disease Control and Prevention to contain the virus. By early March, that conviction was in crisis. “The incompetence has really exceeded what anyone would expect,” he told The New York Times. His astonishment has only intensified since.

Many Americans may understand that testing has failed in this country—that it has been inadequate, in one form or another, since February. What they may not understand is that it is failing, now. In each of the past two weeks, and for the first time since the pandemic began, the country performed fewer COVID-19 tests than it did in the week prior. The system is deteriorating.

Testing is a non-optional problem. Tests permit us to do the most basic task in disease control: Identify the sick, and separate them from the well. When tests are abundant, they can dispel the fear of contagion that has quieted public life. “The only thing that makes a difference in the economy is public health, and the only thing that makes a difference in public health is testing,” Simon Johnson, the former chief economist of the International Monetary Fund, told us. Optimistic timelines suggest that vaccines won’t be widely available, in the hundreds of millions of doses, until May or June. There will be a transition period in which doctors and health-care workers are vaccinated, but teachers, letter carriers, and police officers are not. We will need better testing then. But we need it now, too.

Why has testing failed so completely? By the end of March, Mina had identified a culprit: “There’s little ability for a central command unit to pool all the resources from around the country,” he said at a Harvard event. “We have no way to centralize things in this country short of declaring martial law.” It took several more months for him to find a solution to this problem, which is to circumvent it altogether. In the past several weeks, he has become an evangelist for a total revolution in how the U.S. controls the pandemic. Instead of restructuring daily life around the American way of testing, he argues, the country should build testing into the American way of life.

The wand that will accomplish this feat is a thin paper strip, no longer than a finger. It is a coronavirus test. Mina says that the U.S. should mass-produce these inexpensive and relatively insensitive tests—unlike other methods, they require only a saliva sample—in quantities of tens of millions a day. These tests, which can deliver a result in 15 minutes or less, should then become a ubiquitous part of daily life. Before anyone enters a school or an office, a movie theater or a Walmart, they must take one of these tests. Test negative, and you may enter the public space. Test positive, and you are sent home. In other words: Mina wants to test nearly everyone, nearly every day.

The tests Mina describes already exist: They are sitting in the office of e25 Bio, a small start-up in Cambridge, Massachusetts; half a dozen other companies are working on similar products. But implementing his vision will require changing how we think about tests. These new tests are much less sensitive than the ones we run today, which means that regulations must be relaxed before they can be sold or used. Their closest analogue is rapid dengue-virus tests, used in India, which are manufactured in a quantity of 100 million a year. Mina envisions nearly as many rapid COVID-19 tests being manufactured a day. Only the federal government, acting as customer and controller, can accomplish such a feat.

If it is an audacious plan, it has an audacious payoff. Mina claims that his plan could bring the virus to heel in the U.S. within three weeks. (Other epidemiologists aren’t as sure it would work—at least without serious downsides.) His plan, while costly, is one of the few commensurate in scale to the pandemic: Even if it costs billions of dollars to realize, the U.S. is already losing billions of dollars to the virus every day. More Americans are dying of the coronavirus every month, on average, than died in the deadliest month of World War II. Donald Trump has said that the U.S. is fighting a “war” against an “invisible enemy”; Mina simply asks that the country adopt a wartime economy.

George Packer: We are living in a failed state

We have been covering coronavirus testing since March. For most of that time, the story has been one of failure after failure. But in the past few weeks, something has changed. After months without federal leadership, a loose confederation of scientists, economists, doctors, financiers, philanthropists, and public-health officials has assembled to fill in that gap. They have reexamined every piece of the testing system and developed a new set of tactics to address the months-long testing shortage. Mina’s plan is the most aggressive of these ideas; other groups—such as the new nonprofit Testing for America, founded by private-sector experts who helped the White House in the spring—have advanced their own plans. Taken together, they compose a box of tools that could allow the country to fix its ramshackle house.

The government has also done more in the past month to stimulate the creation of new kinds of tests than it has done in any period of the pandemic so far. The National Institutes of Health has awarded $248 million in grants to companies so that they can scale up alternate forms of COVID-19 testing as quickly as possible. The Centers for Medicare and Medicaid has begun to support the nascent testing market as well. This investment is belated and too meager—by comparison, the government has spent more than $8 billion on vaccine development—but it is significant.

If the new proposals make anything clear, it’s that it is in our power to have an abundance of tests within months—and to return life to normal, or something close to it, even before a vaccine is found. There is a way out of the pandemic.

Today, if you go to the doctor with a dry cough and fever, and get swabbed for COVID-19, you will probably receive a test that was not designed for an out-of-control pandemic. It’s called a “reverse-transcription polymerase chain reaction” test, or PCR, test, and it is one of the miracles of medicine. The PCR technique has allowed us to probe the genomes of the Earth: Its invention, in 1983, cleared the way for the Human Genome Project, the early diagnosis of certain cancers, and the study of ancient DNA. It works, in essence, like a zoom-and-enhance feature on a computer: Using a specific mix of chemicals, called “reagents,” and a special machine, called a “thermal cycler,” the PCR process duplicates a certain strand of genetic material hundreds of millions of times.

When used to test for COVID-19, the PCR technique looks for a specific sequence of nucleotides that is unique to the coronavirus, a snippet of RNA that exists nowhere else. Whenever the PCR machine—as designed and sold, for instance, by the multinational firm Roche—encounters that strand, it makes a copy of both that sequence and a fluorescent dye. If, after multiplying both the strand and the dye hundreds of millions of times, the Roche machine detects a certain amount of the dye, its software interprets the specimen as a positive. To have a “confirmed case of COVID-19” is to have a PCR machine detect the dye in a sample and report it to a technician. Tested time and time again, the PCR technique performs stunningly well: The best-in-class PCR tests can reliably detect, in just a few hours, as few as 100 copies of viral RNA in a milliliter of spit or snot.

The PCR test has anchored the American response to the pandemic. In CDC guidelines written by a council of state epidemiologists, a positive PCR result is the only way to confirm a case of COVID-19. And the Food and Drug Administration, which regulates all COVID-19 tests used in the U.S., judges every other type of test against PCR. Of the more than 62 million COVID-19 tests conducted in the U.S. since March, the overwhelming majority have been PCR.

However, a small but growing pile of clinical evidence—and a sky-scraping stack of real-world accounts—has revealed glaring issues with PCR tests. From a public-health perspective, the most important questions that a test can answer are: Is this person infected and contagious now? and If he’s not contagious, might he be soon? But these are not questions that even a positive PCR result can address. And especially as they’re conducted in the U.S. today, PCR tests do not tell us what we need to know to stop the virus.

Imagine that, at this instant, you are exposed to and infected with the coronavirus. You now have COVID-19—it is day zero—but it is impossible for you or anyone else to know it. In the following days, the virus will silently propagate in your body, hijacking your cells and making millions of copies of itself. Around day three of your infection, there might be enough of the virus in your nasal passages and saliva that a sample of either would test positive via PCR. Soon, your respiratory system will be so crowded with the virus that you will become contagious, spraying the virus into the air whenever you talk or yell. But you likely will not think yourself sick until around day five, when you start to develop symptoms, such as a fever, dry cough, or lost sense of smell. For the next few days, you will be at your most infectious.

And here is the first problem with PCR. To cut off a chain of transmission, public-health workers have to move faster than the virus. If they can test you early—around day three of your infection, for instance—and get a result back in a day or two, they may be able to isolate you before you infect too many people.

But right now, the U.S. is not delivering PCR results anywhere close to that fast. Brett Giroir, the federal coronavirus-testing czar, admitted to Congress last month that even a three-day turnaround time is “not a benchmark we can achieve today.” As an outbreak raged in Arizona this summer, some PCR results took 14 days or more to come back. That’s worse than useless—“I would not call that a test,” Johnson, the economist, told us—because most bouts of COVID-19 last 14 days or fewer. “The majority of all U.S. tests are completely garbage, wasted,” Bill Gates, who has helped fund COVID-19 testing, recently said.

After your symptoms start around day five, you might remain symptomatic for several days to several months. But some recent studies suggest that by day 14 or so—nine days after your symptoms began—you are no longer infectious, even if you are still symptomatic. By then, there is no longer live virus in your upper respiratory system. But because millions of dead virus particles line your mouth and nasal cavity, and because they contain strands of intact RNA, and because the PCR technique is very sensitive, you will still test positive on a PCR test. For weeks, in fact, you may test positive via PCR, even after your symptoms abate.

And here is PCR’s second problem: By this point in your illness, a positive PCR test does not mean what you might expect. It does not mean that you are infectious, nor does it necessarily mean that there is live SARS-CoV-2 virus in your body. It does not make sense to trace any contacts you’ve had in the past five days, because you did not infect them. Nor does it make sense for you to stay home from work. But our country’s public-health infrastructure cannot easily distinguish between a day-two positive and a day-35 positive.

The final issue with PCR tests is simple: There aren’t enough of them. The U.S. now runs more than 700,000 COVID-19 tests a day. On its own terms, this is a stupendous leap, a nearly 800-fold increase since early March. But we may be maxing out the world’s PCR capacity; supply chains are straining and snapping. For months, it has been difficult for labs to get the expensive chemical reagents that allow for RNA duplication. Earlier this summer, there was a global run on the tips of pipettes—the disposable plastic basters used to move liquid between vials. Sometimes the bottleneck is PCR machines themselves: As infections surged in Arizona last month, and people lined up to be tested, the number of tests far exceeded the machines’ capacity to run them.

When tests dwindle, the entire medical system suffers. In Arizona, many doctors’ offices were short-staffed at the peak of the outbreak, because any doctor exposed to the virus needed to test negative before returning to work, and the system simply couldn’t handle the volume of tests. “We’ve had people out seven to 10 days” waiting for a negative result, Catherine Gioannetti, the medical director of health and safety for Arizona Community Physicians, told us. “It’s essentially a broken system, because we don’t have results in a timely fashion.”

If labs don’t have the capacity to turn around doctors’ tests, which are often fast-tracked, they definitely do not have the capacity to test contagious people who are wholly asymptomatic. These silent spreaders may remain infectious for weeks but never develop any symptoms. They are the virus’s “secret power,” one testing executive told us, and they account for 20 to 40 percent of all infections. Some evidence suggests that they may be more infectious than symptomatic people, carrying higher viral loads for longer.

The challenge is clear: We need an enormous number of tests. As some have argued since the spring, the American population at large—and not just feverish, coughing people—has to be screened. Let’s say, for instance, that you wanted to test everyone in the U.S. once a week. That’s 45 million tests a day. How can we get there?

In the immediate future, the only way to increase testing is to squeeze more tests out of the existing PCR system. Our best bet to do so fast is through a technique called “pooling,” which could get a few hundred thousand more tests out of the system every day.

Pooling is straightforward: Instead of testing each sample individually, laboratories combine some samples, then test that “pooled” sample as one. The technique was invented by Robert Dorfman, a Harvard statistician, to test American soldiers for syphilis during World War II. Today it is commonly used by public-health labs to test for HIV. It works as follows: A lab technician mixes 50 HIV samples together, then tests this pool. If the result is negative, then none of the patients has HIV—and the researcher has evaluated 50 samples with the same materials it takes to run one test.

But if the pooled sample is positive, a new phase starts. The technician pools the same specimens again, this time into smaller groups of 10, and retests them. When one of these smaller pools is positive, she tests each individual sample in it. By the end of the process, she has tested 50 people for HIV, but used only a dozen or so tests. This approach saves her hundreds of tests over the course of a day.

Pooling is a great first step to maximizing our test supply, Jon Kolstad, an economist at UC Berkeley, told us. This is in part because regulators and public-health officials are already familiar with it. The FDA has told Quest Diagnostics, LabCorp, and BioReference, three major commercial laboratories, that they can start pooling a handful of coronavirus samples at a time. In some parts of New England that haven’t seen much of the virus, pooling could triple or even quadruple the number of tests available, a team at the University of Nebraska has found.

But pooling is only a stopgap. It works best for diseases that are relatively rare, such as HIV and syphilis. If a disease is too common, then the work of pooling—the laborious mixing and remixing of samples—is more work than it’s worth. (About twice as many Americans have been infected with the coronavirus as have contracted  HIV since 1981.) In Arizona and some southern states burning with COVID-19, traditional pooling would not be worth the effort, the same Nebraska team found.

Kolstad and Johnson, the MIT economist, are experimenting with ways to increase the efficiency of pooling. By grouping samples more deliberately, they can create larger pools of people with similar risksA group of office workers might be at lower risk than a group of meatpackers who work close together, and even within a meatpacking plant, workers on one side of the plant might be at greater risk than those on the other. And because pooling saves money, companies and colleges and schools could run more tests. This would create a virtuous cycle. Each day, a person has a certain chance of being infected that varies with the prevalence of the disease in a community. Test every day, and there is simply less time between tests in which a person could have been infected. This makes it possible to build larger pools of people who are likely negative.

Starting up these systems would require clearing logistical and regulatory hurdles—a positive coronavirus sample is a low-level biohazard, and the FDA regulates it as such. Dina Greene, who directs lab testing for Kaiser Permanente in Washington State, says that contamination problems are already difficult for labs to manage, and would be more so if labs have to manually mix together samples.

Kolstad has been thinking through this problem. His team is experimenting with a different technique, which one might call “intermediate pooling.” Instead of having labs make pools on the back end, Kolstad proposes deploying trained nurses in mobile pooling labs in retrofitted vans. It would work well for nursing homes, he says: The nurses might arrive at a certain time every day, test every employee, pool the samples in the van, and then drop them off at a nearby clinical lab. (Because the FDA regulates pooling in clinical labs more strictly than in this type of “surveillance testing,” it may also be easier to obtain FDA approval for this plan.) Kolstad and his team are trying out this technique with a network of nursing homes in the Boston area, and delivering the pooled tests to a nearly complete, fully automated COVID-19 testing facility run by Gingko Bioworks, a $4 billion start-up in Cambridge that is pitching another method to scale up U.S. testing, one that could vastly increase the pace of processing.

Since its founding in 2009, Ginkgo Bioworks has specialized in synthesizing new kinds of bacteria for use in industrial processes. Its engineers spin new forms of DNA using genetic-sequencing machines made by Illumina, a large and publicly traded biotechnology company. But in the spring, as viral testing buckled, Ginkgo’s engineers realized that their Illumina machines could be put to another use: Instead of creating genes, they could identify existing ones—and do so much faster than a PCR machine can.

Unlike PCR machines, which can analyze at most hundreds of individual samples per run, sequencing machines can read thousands of samples simultaneously. A high-end PCR machine, operated by a round-the-clock staff, can run up to 1,000 samples a day; a single Illumina machine can read more than 3,000 samples in half that time. Ginkgo has sharpened that advantage by building its fully automated factory in Boston, centered on Illumina machines, which it says could test about 250,000 samples a day. It aims to open the facility by mid-October; in two months more, another three could go up and Ginkgo could be testing 1 million samples each day.

The company has designed its supply chain to withstand high demand. It has rejected some reagents, for instance, because it doesn’t trust that there will be enough of them; it uses saliva samples, not swabbed nose or throat samples, because it does not think there are enough swabs in the world to meet demand. The genetic-sequencing supply chain is already built for such scale because other automated factories—doing noninvasive neonatal testing, for example—already use Illumina machines.

Both Ginkgo and an Illumina-backed start-up, Helix, have received NIH grants to rapidly scale up their testing. If the technique receives FDA approval, as many expect, the two companies could as much as triple the country’s testing capacity. “In three months, I think we could be at between 1 and 3 million additional tests per day in this country, without any problem at all,” John Stuelpnagel, a bioscience entrepreneur and one of the founders of Illumina, told us.

The approach has its challenges. Any samples must be shipped to one of Ginkgo’s or Helix’s centralized testing locations, which imposes a huge logistical obstacle to scaling up. The incumbent testing companies—Quest and LabCorp—have achieved dominance because of their ability to collect samples from places where they’re tested. But in Ginkgo’s full vision, 1 million tests will cover far more than 1 million people.

The key to this approach is “front-end pooling.” Imagine that every day, when kids arrive in their classroom, they briefly remove their mask and spit into a bag. (It is a perfect plan for second graders.) The bag would then be shipped to the nearest Ginkgo factory, which could test the pooled sample and deliver a single result for the classroom by the next morning. “If you pool together one classroom, and test that classroom together, then if you get a positive, you can send the whole classroom home,” Blythe Adamson, an economist and epidemiologist at the nonprofit Testing for America, told us. “For children, it protects their privacy—we don’t know which student” tested positive.

Front-end pooling could also drive costs down, partly by saving on materials. “Do 10 people spit in one bag? That’s one-tenth the cost,” Jason Kelly, Ginkgo’s chief executive, told us. “It’s logistically simpler, because one bag shows up, not 10, so there’s 10 times less unboxing, 10 times less robotic movement.” The challenge, he said, is chiefly one of industrial design, not molecular biology: There is no FDA-approved device, at present, that will let 10 kids safely spit into one vial. We should have federally backed development and fast regulatory approval for that kind of device, Kelly said.

The Ginkgo sequencing approach and front-end pooling have never been tried before, because they make sense only in a pandemic. Only at the scale of tens of thousands of tests do Ginkgo tests start to cost less than PCR, Adamson said. But at that scale, their cost drops quickly in comparison—possibly down to $20, Stuelpnagel said, if not $10, compared with more than $100 for a PCR test.

“You’d never do [any of this] for HIV,” Kelly said. “It’s only in a pandemic you go, ‘Oh my God, we’re undertesting by a factor of 10.’”

But what if testing needs to scale up not 10 times, but 20, or 50, or 100 times? That’s where another type of test—an antigen test—comes in.

At the same time that Ginkgo and other next-gen sequencing tests should come online, antigen tests will be scaling up. Unlike a PCR or a Ginkgo-style test, an antigen test does not identify any of the virus’s genetic material. Instead, it looks for an antigen, a slightly redundant name for any chemical that’s recognized by the test. Antigen tests aren’t as sensitive as genetic tests, but what they sacrifice in accuracy, they make up in speed, cost, and convenience. Most important, an antigen test can be conducted quickly at a “point of care” location, such as a doctor’s office, nursing home, or hospital.

Two of the most anticipated such tests are already on the market. Manufactured by two companies, Quidel and Becton, Dickinson and Company, they look for an antigen called “nucleocapsid,” which is plentiful in the SARS-CoV-2 virus. The companies say they will be making a combined 14 million tests a month by the end of September; for comparison, the U.S. completed 23 million total tests in July. This scale alone will make this type of test an important factor in fall testing. Hospitals and doctors told us they are eager to get their hands on antigen tests, in part because they’re worried about dealing with COVID-19 during the coming flu season. In years past, if a patient had a cough and a runny nose in December, she would likely be diagnosed with the flu, even if she tested negative on a rapid flu test. “But now we can’t presume [patients] have the flu,” because they might have COVID-19, says Natasha Bhuyan, the West Coast medical director for One Medical, a chain of primary-care clinics. An antigen test seems to offer a way out of this dilemma.

The tests cost less than half as much as standard PCR tests, and they don’t need to be sent away to a lab. They can deliver a result in 15 minutes. But this approach has downsides. While the tests work well enough, successfully identifying most people with high viral loads, they have sometimes delivered false positives. Last week, Ohio Governor Mike DeWine tested positive on the Quidel test, leading him to cancel a meeting with President Trump. But later that day, he tested negative, three times, when analyzed by PCR.

And while these tests will be useful, they have their own supply-chain drawbacks. Both companies’ tests can be interpreted only with a proprietary reader, and while many clinics and offices already have these readers on hand, neither company is prepared to mass-produce them at the same scale as the tests. (Quidel now makes 2,000 of its readers a month, but is aiming to scale to 7,000 a month by September, a spokesperson told us.) Because both tests look for nucleocapsid, which exists only inside the coronavirus, they need a way to sever the virus’s outer membrane. This requires more reagents. For many technicians, these drawbacks aren’t worth the benefits. “Most people who are real lab experts are steering away from all that stuff because they can’t justify it,” Greene, the Kaiser lab director, said.

The readers are a particular sticking point for Michael Mina, the Harvard epidemiologist. He calls the BD and Quidel systems “Nespresso tests,” because, just as a Nespresso pod can transform into coffee only through a Nespresso brewer, they can deliver results only when their readers are at hand. “What I want is the instant coffee of tests,” he told us. What if there was an antigen test that could be made in huge numbers and didn’t require a specialized reader? What if it worked more like a pregnancy test—a procedure you can do at home, and not only at a doctor’s office?

Such tests exist—and have existed since April—and they are made by e25 Bio, a 12-person company in Cambridge. An e25 test is a paper strip, a few inches long and less than an inch wide. It needs only some spit, a saline solution, and a small cup—and it can deliver a result in 15 minutes. Like a pregnancy test, the strip has a faint line across its lower third. If you expose the strip to a sample and it fills in with color, then the test is positive. It does not require a machine, a reagent, or a doctor to work.

Its unusual quality is that it does not look for the same antigen as other tests. Instead of identifying nucleocapsid, the e25 test is keyed to something on the outside of the virus. It reacts to the presence of the coronavirus’s distinctive spike protein, the structure on the virus’s “skin” that allows it to hook onto and enter human cells. “I think we’re the only company in North America that has developed a spike antigen test,” Bobby Brooke Herrera, e25’s co-founder and chief executive, told us.

This has several advantages. It means, first, that the e25 test does not have to rupture the virus, which is why it doesn’t need reagents. And it means, second, that the e25 test is actually looking for something more relevant than the virus’s genetic material. The spike protein is the coronavirus’s most important structure—it plays a large part in determining the virus’s infectiousness, and it’s what both antibodies and many vaccine prototypes target—and its presence is a good proxy for the health of the virus generally. “We’ve developed our test to detect live viruses, or, in other words, spike protein,” Herrera said.

Working with two manufacturers, e25 thinks that it could make 4 million tests a month as soon as it receives FDA approval. Within six weeks of approval, it could make 20 million to 40 million tests a month. In short, e25 could single-handedly add as many as 1.2 million tests a day to the national total.

But FDA approval has not yet arrived, because the FDA compares every test to PCR, and no antigen test, however advanced, can stand up to the accuracy and sensitivity of the PCR technique. “The FDA, early on in the outbreak, said we had to follow a rubric of 80 percent sensitivity compared to PCR. How they got that number, I’m uncertain, but my best guess is it came from influenza epidemics in the past,” Herrera said.

This requirement has made antigen tests worse, Herrera argues, because it causes manufacturers to prioritize sensitivity at the cost of speed or convenience. It’s why other antigen tests use readers, or centrifuges, or look for nucleocapsid, he contends. By slightly weakening those guidelines, to 60 or 70 percent sensitivity, the FDA could let cheaper at-home tests come to market. The models that e25 uses show that even an at-home test that caught 50 percent of positives and 90 percent of negatives could detect outbreaks and reduce COVID-19 transmission.

Recall the coronavirus’s infection clock—how, from day zero of an infection to day five, the amount of the virus in your system exponentially increases; how it begins to ebb with the onset of symptoms; how, by day 14 or so, the PCR test is likely detecting only the refuse RNA of dead virus. While antigen tests need the equivalent of 100,000 viral strands per milliliter, a typical PCR test can detect a positive from as little as 1,000 strands per milliliter. There is only about a day at the beginning of an infection when the two tests would give different results—when there are more than 1,000 viral strands per milliliter of your saliva or snot but fewer than 100,000, according to Dan Larremore, a mathematician at the University of Colorado at Boulder. During that period—approximately day two or day three of an infection—antigen tests are truly inferior to PCR tests.

Yet the opposite is true as COVID-19 fades: There are potentially weeks at the end of an infection when there is enough viral RNA to clear the threshold for a positive PCR test but not enough to set off an antigen test. During that period, antigen tests, such as e25’s, outperform PCR tests, Mina argues, because they identify only people who are still contagious. So why, he asks, are they judged against PCR tests—and kept off the market—for failing to find the virus when there is no intact virus to find?

Antigen tests are not better than PCR tests in every instance. When someone at a hospital presents with severe COVID-19-like symptoms, for example, health-care workers cannot risk a false negative: They will need a PCR test. Some experts worry that at-home tests will have a much lower accuracy rate than advertised. Laboratory tests are conducted by professionals on machines they are familiar with, but amateurs will conduct at-home tests, which risks introducing errors not captured by official ratings or even imagined by regulators. At a national scale, this could mean that someone might have COVID-19, fail to realize it, and infect other people. “What’s concerning is the salami slicing of sensitivity. A percent here, a percent there, and pretty soon you’re talking real people,” Alex Greninger, a laboratory-medicine professor at the University of Washington, told us. Jennifer Nuzzo, an epidemiologist at the Johns Hopkins Center for Health Security, told us that it’s not yet clear whether people who receive a positive result on an at-home test will report that information to health authorities and choose to self-isolate.

But given that they are cheaper than PCR tests, have a faster turnaround time, and can be conducted at home, these paper tests do seem different, in a useful way. In some cases, they answer a more helpful question than PCR tests. There is good evidence to infer that a high viral load, which is what antigen tests detect, is correlated with infectiousness. The more virus in your body, the more contagious you are.

In that light, paper antigen tests aren’t SARS-CoV-2 tests at all, not like PCR tests are. They are rapid, cheap COVID-19 contagiousness tests. That shift in thinking, Mina argues, should undergird a shift in our national strategy.

Mina wants to coat the country in COVID-19 contagiousness tests. To understand the scale of his vision, start with the closest American analogue, the ubiquitous, paper-based, inexpensive at-home pregnancy test. Americans use 20 million of those each year. This is not sufficient for Mina’s plan. “Ideally, we’re making way more than 20 million [paper tests] a day,” Mina said. Entering a grocery store? Take a test first. Getting on a flight? There’s a test station at the gate. Going to work? Free coffee is provided with your mandatory test. He began pitching the idea as a moonshot in July, but it quickly took hold. By the end of the month, Howard Bauchner, the editor in chief of The Journal of the American Medical Associationgushed on a podcast that ubiquitous tests were “the best way we can get back to a semblance of working society.”

The idea has gained other advocates. Last month, a panel of experts convened by the Rockefeller Foundation called for the U.S. to do 3.5 million rapid antigen tests a day, or 25 million a week—five times more than the number of PCR tests they recommended. The researchers compiled a list of 12 rapid tests in development, including e25’s, and called for an aggressive government-led effort to support them. (The Rockefeller Foundation has also provided funding to the COVID Tracking Project at The Atlantic.) “These sort of tests are on the horizon, but getting them into the hands of everyone who needs them—schools, employers, health providers, public essential workers, vulnerable communities—will require the muscle that only the federal government can provide,” the experts wrote.

The muscle, specifically, of a wartime economy. The experts called for the White House to invoke the Defense Production Act, a Truman-era law that allows the federal government to compel companies to mass-produce goods in moments of national crisis. (Manufacturers are compensated for their effort at a fair price.) Only naked federal authority could push production fast enough to make enough tests in time to curb the virus, they wrote.

Herrera, the e25 executive, has been waiting for months for the government to invoke such power. There is essentially no resource constraint on the raw materials that make up antigen tests, but there is a profound limit to available productive capacity. “Being able to manufacture these products,” Herrera said, “is where the bottleneck lies.” And after it has the tests, Herrera believes, the company will need help sending them where they’re most needed. If testing companies are to save the world, they need federal support to do it.

And here is the tragedy—and the promise—of Mina’s moonshot: To fix testing, the federal government must do exactly what it has declined to do so far. Why is testing still a problem? Partly because the CDC and the FDA bickered in February and delayed by weeks the initial rollout of COVID-19 tests. Partly because infections continued to grow in the spring and summer, further boosting the number of tests needed to track the virus. But those reasons alone still do not explain the fundamental issue: Why has the U.S. never, not since the pandemic began, had enough tests?

The answer is because the Trump administration has addressed the lack of testing as if it is a nuisance, not a national-security threat. In March and April, the White House encouraged as many different PCR companies to sell COVID-19 tests as possible, declining to endorse any one option. While this idea allowed for competition in theory, it was a nightmare in practice. It effectively forced major labs to invest in several different types of PCR machines at the same time, and to be ready to switch among them as needed, lest a reagent run short. Today, the government cannot use the Defense Production Act to remedy the shortage of PCR machines or reagents—because the private labs running the tests are too invested in too many different machines.

Because of its trust in PCR, and its assumption that the pandemic would quickly abate, the administration also failed to encourage companies with alternative testing technologies to develop their products. Many companies that could have started work in April waited on the sidelines, because it wasn’t clear whether investing in COVID-19 testing would make sense, Sri Kosaraju, a member of the Testing for America governing council and a former director at JP Morgan, told us.

The Trump administration hoped that the free market would right this imbalance. But firms had no incentive to invest in testing, or assurance that their investments would pay off. Consider the high costs of building an automated testing factory, as Ginkgo is doing, said Stuelpnagel, the Illumina co-founder. A company would typically amortize the costs of that investment over three to five years. But that calculation breaks down in the pandemic. “There’s no way that we’re doing high-throughput COVID testing five years from now. And I hope there’s not COVID testing being done three years from now that would require this scale of lab,” he said. Companies aren’t built to deal with that level of uncertainty, or to serve a market that would dramatically shrink, or disappear altogether, if their product did its job. Even if the experimentation would benefit the public, it doesn’t make sense for individual businesses to take on those risks.

So nothing happened—for months. Only in the past few weeks has the federal government begun to address these concerns. The NIH grants awarded to Ginkgo, Helix, Quidel, and others were aimed, in part, at providing capital that would let businesses scale up quickly. And the Centers for Medicare and Medicaid has started to ensure that demand will exist for an experimental test: It has promised to buy Quidel or BD tests for every nursing home in the country.

But even if those companies succeed in delivering what they’ve promised, life will not go back to normal. An extra 1 million tests a day will allow us to ramp up contact-tracing operations and slow down the virus, but they will not change the texture of daily life in the pandemic, especially if there is another resurgence of the virus in the winter. For that, Mina’s moonshot is required. It will require much more than the $200 million the federal government has invested in testing technology so far, and it will require the full might of the federal government, with its unique ability to coerce manufacturing capacity. But its costs are not astronomical. If every paper test costs $1, as Mina hopes, and every American takes a test once a week, then his plan will cost about $1.5 billion a month. Congress has already authorized at least $7 billion to fix testing that the Trump administration had declined, for months, to spend. And even if Mina’s plan cost $300 million each day, the annual expense would amount to a fraction—about 3 percent—of the more than $3 trillion Congress has already spent dealing with the economic fallout of the pandemic. Yet the plan wouldn’t merely mitigate the harm of the pandemic. It could end it. To escape the pandemic in this way, the U.S. must make hundreds of millions of contagiousness tests—tests that are not perfect, but just good enough.

Mass-producing a cheap thing fast is, as it happens, something the United States is very good at, and something this country has done before. During the Second World War, the U.S. realized that the most effective way of shipping goods to Europe was not to use the fastest ship, but to use cheap “Liberty ships,” which were easy to mass-produce. The Allies “created this model of a ship that was kind of cheap, not as fast as they could make it, and not as good as they could make it,” Mark Wilson, a historian at the University of North Carolina at Charlotte, told us. “They were building cheap—one might say disposable—ships. They weren’t very good. But they just wanted to out-volume their opponents.”

We must out-volume the virus, and what will matter is not the strength of any one individual ship, but the strength of the system it is part of. When the FDA regulates tests, though, it looks at the sensitivity and specificity of a single test—how well the test identifies illness in an individual—not at how the test is part of a testing regimen meant to protect society. For this reason, Mina proposes that the FDA make room for the CDC or the NIH to oversee the use of contagiousness tests. “I think the CDC could potentially create a certification process really simply. They are the public-health agency, and could say, ‘We will evaluate different manufacturers. None of these will be fully regulated by law, but here are the ones you should or should not choose.’”

Paper tests do have downsides. Testing tens of millions of people each day would be an unprecedented biotechnical intervention in the country, and it might have unpredictable, nasty side effects. Mina’s plan is “being pushed without really thinking through the operational consequences,” Nuzzo said on a recent press call. Brett Giroir, the federal testing czar, has worried that a deluge of positive paper tests could lead asymptomatic people to swamp the rest of the medical system. “You do not beat the virus by shotgun testing everybody, all the time,” he said on the same call. Paper tests are based on an inference about human behavior. For example, if people knew that every paper test would catch only seven or eight infections out of every 10 (compared with PCR, which would catch all 10), would they keep taking them? Would the country’s testing system split in two, delivering PCR tests for the rich and cheap paper tests for the poor? Each way of testing for the virus is not only a technology or a medical device. Each is its own hypothesis about public health, human behavior, and market forces.

So here is what May 2021 could look like: Vaccines are rolling out. You haven’t gotten your dose yet, but you are no longer social distancing. When your daughter walks into her classroom, she briefly removes her mask and spits into a plastic bag; so do all the other children and the teacher. The bag is then driven across three states and delivered to the nearest Ginkgo processing facility. When you arrive at work, you spit into a plastic cup, then step outside to drink coffee. In 15 minutes, you get a text: You passed your daily screen and may proceed into the office. You still wear your mask at your desk, and you try to avoid common areas, but local infection levels are down in the single digits. That night, you and your family meet your parents at a restaurant, and before you proceed inside, you all take another contagiousness test. It’s normal, now, to see the little cups of saliva and saline solution, each holding a strip of color-changing paper, sitting on tables near the entrance of every public place. And before you fall asleep, you get a text message from the school district. Nobody in your daughter’s class tested positive this morning—instruction can happen in person tomorrow.

There is no technical obstacle to that vision. There is only a dearth of political will. “The lack of testing is a motivation problem,” Stuelpnagel said. “It’s going to take a lot of effort, but it should take a lot of effort, and we should be willing to take that effort.” Mina is frustrated that the answer is so close, and so doable, but not yet something the government is considering. “Let’s make the all-star team of people in this field, pay them whatever they need to be paid, put billions of dollars in, and get a working test in a month that could be truly scalable. Take it out of the free-market, capitalistic world and say: ‘This is a national emergency’—which,” he said, “it is.”

Can a Nice Doctor Make Treatments More Effective?

In the age of the internet, it’s easier than ever to pull together lots of information to find the best doctor. And if you’re like most patients, the metric you probably rely on most is the doctor’s credentials. Where did she go to school? How many patients has he treated with this condition?

You might also read some Yelp reviews about how nice this doctor is; how friendly and how caring. But all that probably seems secondary to the doctor’s skills; sure, it would be great to have a doctor whom you actually like, but that’s not going to influence your health the way the doctor’s competence will.

But our research in the psychology department at Stanford University suggests that this view is mistaken. We found that having a doctor who is warm and reassuring actually improves your health.

The simple things a doctor says and does to connect with patients can make a difference for health outcomes.

Even a brief reassurance to a patient from a doctor might relieve the patient’s symptoms faster. In a recent study that one of us conducted, our research group recruited 76 participants to receive a skin prick test, a common procedure used in assessing allergies. The provider in this study pricked participants’ forearms with histamine, which makes skin itchy and red.

Then, the doctor examined the allergic reactions. For some patients, the doctor examined them without saying much. But for other patients, the doctor had some words of encouragement. He told them: “From this point forward, your allergic reaction will start to diminish, and your rash and irritation will go away.” It turns out that this one sentence of assurance from a provider led patients to report that their reactions were less itchy — even though the doctor didn’t give any medication or treatment along with his words. Words alone from the provider relieved patients’ symptoms.

This tells us that a physician’s words might be more powerful than we normally realize. And research shows that it is not only when patients are taking placebos that demeanor matters. In fact, provider words influence the efficacy of even our most powerful drugs and treatments.

But as anyone who has been on the receiving end of a terse “You’re fine” knows, it’s not just what you say, it’s how you say it.

In another study one of us worked on, we assessed whether the same words from a doctor influence patients differently depending on how warm or competent the doctor seemed. Again, patients received a histamine skin prick. Depending on what experimental group they were assigned to, patients met a provider trained to act in one of two very different ways. One group met the provider many of us dream of: she acted both warm and competent, calling patients by name, smiling, chatting and making eye contact. Her office was spotless, she spoke clearly and confidently, and she pulled off the medical procedures without a hitch.

The other group, however, met the kind of doctor all too many of us have encountered: glued to the computer screen throughout the exam, the provider didn’t bother introducing herself and asked questions only to gather practical information. She also stumbled through some of the procedures in the messy exam room and sounded rather unsure of herself.

In both groups, the provider gave patients a cream that she said was an antihistamine to reduce the allergic reaction and decrease itching. The cream was merely unscented hand lotion: a placebo. (A benefit of doing this research in the lab is that for the purposes of the study, we can temporarily lead patients to believe something that is untrue, something doctors could never do in a real clinic visit.)

Decades of robust literature on placebo effects demonstrate that, even without any active ingredients, this cream should reduce the allergic reaction. But no one had examined how the doctor’s demeanor might influence the effects of a placebo treatment.

Our study revealed that the placebo cream reduced participants’ allergic reactions only when the provider projected warmth and competence. When the provider acted colder and less competent, the placebo cream had no effect. It seems that it’s not just what the doctor says about a treatment that matters. It matters how the doctor who says it engages with patients. Doctors who are warmer and more competent are able to set more powerful expectations about medical treatments. Those positive expectations, in turn, have a measurable impact on health.

So, we saw that when the provider projected both desirable qualities of warmth and competence, her words had an effect. When she projected neither, they did not.

What about a provider who seems competent, but not warm? One other group of patients met a provider who seemed highly competent but remained businesslike and distant throughout the interaction, and they did not respond to the placebo cream as much as when the provider acted warm and competent.

Patients of even the most accomplished and skillful doctors may benefit more when that doctor also connects with them.

All of this research suggests that doctors who don’t connect with their patients may risk undermining a treatment’s success. Doctor-patient rapport is not just a fluffy, feel-good bonus that boosts Yelp reviews, but a component of medical care that has important effects on a patient’s physical health. Particularly as artificial intelligence promises a world where we don’t need to go to the doctor for minor questions, we should not overlook the value of interacting with a human doctor and hearing words of encouragement.

And while physicians may worry that building rapport with patients requires too much time in a health care setting with visits that are already too short, there are simple ways to build warmth and competence — such as smiling, looking patients in the eye and asking their names — that don’t tax doctors beyond their limits.

We often think the only parts of medical care that really matter are the “active” ingredients of medicine: the diagnosis, prognosis and treatment. But focusing only on these ingredients leaves important components of care underappreciated and underutilized. To really help people flourish, health care works better when it includes caring.

 

This article was originally published in The New York Times. Read the original article.

H.I.V. Is Reported Cured in a Second Patient, a Milestone in the Global AIDS Epidemic

For just the second time since the global epidemic began, a patient appears to have been cured of infection with H.I.V., the virus that causes AIDS.

The news comes nearly 12 years to the day after the first patient known to be cured, a feat that researchers have long tried, and failed, to duplicate. The surprise success now confirms that a cure for H.I.V. infection is possible, if difficult, researchers said.

The investigators are to publish their report on Tuesday in the journal Nature and to present some of the details at the Conference on Retroviruses and Opportunistic Infections in Seattle.

Publicly, the scientists are describing the case as a long-term remission. In interviews, most experts are calling it a cure, with the caveat that it is hard to know how to define the word when there are only two known instances.

Both milestones resulted from bone-marrow transplants given to infected patients. But the transplants were intended to treat cancer in the patients, not H.I.V.

Bone-marrow transplantation is unlikely to be a realistic treatment option in the near future. Powerful drugs are now available to control H.I.V. infection, while the transplants are risky, with harsh side effects that can last for years.

But rearming the body with immune cells similarly modified to resist H.I.V. might well succeed as a practical treatment, experts said.

“This will inspire people that cure is not a dream,” said Dr. Annemarie Wensing, a virologist at the University Medical Center Utrecht in the Netherlands. “It’s reachable.”

Dr. Wensing is co-leader of IciStem, a consortium of European scientists studying stem cell transplants to treat H.I.V. infection. The consortium is supported by AMFAR, the American AIDS research organization.

The new patient has chosen to remain anonymous, and the scientists referred to him only as the “London patient.”

“I feel a sense of responsibility to help the doctors understand how it happened so they can develop the science,” he told The New York Times in an email.

Learning that he could be cured of both cancer and H.I.V. infection was “surreal” and “overwhelming,” he added. “I never thought that there would be a cure during my lifetime.”

At the same conference in 2007, a German doctor described the first such cure in the “Berlin patient,” later identified as Timothy Ray Brown, 52, who now lives in Palm Springs, Calif.

That news, displayed on a poster at the back of a conference room, initially gained little attention. Once it became clear that Mr. Brown was cured, scientists set out to duplicate his result with other cancer patients infected with H.I.V.

In case after case, the virus came roaring back, often around nine months after the patients stopped taking antiretroviral drugs, or else the patients died of cancer. The failures left scientists wondering whether Mr. Brown’s cure would remain a fluke.

Mr. Brown had had leukemia, and after chemotherapy failed to stop it, needed two bone-marrow transplants.

The transplants were from a donor with a mutation in a protein called CCR5, which rests on the surface of certain immune cells. H.I.V. uses the protein to enter those cells but cannot latch on to the mutated version.

Mr. Brown was given harsh immunosuppressive drugs of a kind that are no longer used, and suffered intense complications for months after the transplant. He was placed in an induced coma at one point and nearly died.

Timothy Ray Brown, the first person to be cured of H.I.V., almost died during the treatment.CreditGrant Hindsley for The New York Times
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Timothy Ray Brown, the first person to be cured of H.I.V., almost died during the treatment.CreditGrant Hindsley for The New York Times

“He was really beaten up by the whole procedure,” said Dr. Steven Deeks, an AIDS expert at the University of California, San Francisco, who has treated Mr. Brown. “And so we’ve always wondered whether all that conditioning, a massive amount of destruction to his immune system, explained why Timothy was cured but no one else.”

The London patient has answered that question: A near-death experience is not required for the procedure to work.

He had Hodgkin’s lymphoma and received a bone-marrow transplant from a donor with the CCR5 mutation in May 2016. He, too, received immunosuppressive drugs, but the treatment was much less intense, in line with current standards for transplant patients.

He quit taking anti-H.I.V. drugs in September 2017, making him the first patient since Mr. Brown known to remain virus-free for more than a year after stopping.

“I think this does change the game a little bit,” said Dr. Ravindra Gupta, a virologist at University College London who presented the findings at the Seattle meeting. “Everybody believed after the Berlin patient that you needed to nearly die basically to cure H.I.V., but now maybe you don’t.”

Although the London patient was not as ill as Mr. Brown had been after the transplant, the procedure worked about as well: The transplant destroyed the cancer without harmful side effects. The transplanted immune cells, now resistant to H.I.V., seem to have fully replaced his vulnerable cells.

Most people with the H.I.V.-resistant mutation, called delta 32, are of Northern European descent. IciStem maintains a database of about 22,000 such donors.

So far, its scientists are tracking 38 H.I.V.-infected people who have received bone-marrow transplants, including six from donors without the mutation.

The London patient is 36 on this list. Another one, number 19 on the list and referred to as the “Düsseldorf patient,” has been off anti-H.I.V. drugs for four months. Details of that case will be presented at the Seattle conference later this week.

The consortium’s scientists have repeatedly analyzed the London patient’s blood for signs of the virus. They saw a weak indication of continued infection in one of 24 tests, but say this may be the result of contamination in the sample.

The most sensitive test did not find any circulating virus. Antibodies to H.I.V. were still present in his blood, but their levels declined over time, in a trajectory similar to that seen in Mr. Brown.

None of this guarantees that the London patient is forever out of the woods, but the similarities to Mr. Brown’s recovery offer reason for optimism, Dr. Gupta said.

“In a way, the only person to compare with directly is the Berlin patient,” he said. “That’s kind of the only standard we have at the moment.”

Most experts who know the details agree that the new case seems like a legitimate cure, but some are uncertain of its relevance for AIDS treatment overall.

“I’m not sure what this tells us,” said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases. “It was done with Timothy Ray Brown, and now here’s another case — ok, so now what? Now where do we go with it?”

One possibility, said Dr. Deeks and others, is to develop gene-therapy approaches to knock out CCR5 on immune cells or their predecessor stem cells. Resistant to H.I.V. infection, these modified cells should eventually clear the body of the virus.

(CCR5 is the protein that He Jiankui, a scientist in China, claimed to have modified with gene editing in at least two children, in an attempt to make them resistant to H.I.V. — an experiment that set off international condemnation.)

Several companies are pursuing gene therapies but have not yet been successful. The modification must target the right number of cells, in the right place — only the bone marrow, for example, and not the brain— and tweak only the genes directing production of CCR5.

“There are a number of levels of precision that must be reached,” said Dr. Mike McCune, a senior adviser on global health to the Bill and Melinda Gates Foundation. “There are also concerns that you might do something untoward, and if so you might wish to have a kill switch.”

Several teams are working on all of these obstacles, Dr. McCune said. Eventually, they may be able to develop a viral delivery system that, when injected into the body, seeks out all CCR5 receptors and deletes them, or even a donor stem cell that is resistant to H.I.V. but could be given to any patient.

“These are dreams, right? Things on the drawing table,” Dr. McCune said. “These dreams are motivated by cases like this — it helps us to imagine what might be done in the future.”

One important caveat to any such approach is that the patient would still be vulnerable to a form of H.I.V. called X4, which employs a different protein, CXCR4, to enter cells.

“This is only going to work if someone has a virus that really only uses CCR5 for entry — and that’s actually probably about 50 percent of the people who are living with H.I.V., if not less,” said Dr. Timothy J. Henrich, an AIDS specialist at the University of California, San Francisco.

Even if a person harbors only a small number of X4 viruses, they may multiply in the absence of competition from their viral cousins. There is at least one reported case of an individual who got a transplant from a delta 32 donor but later rebounded with the X4 virus. (As a precaution against X4, Mr. Brown is taking a daily pill to prevent H.I.V. infection.)

Mr. Brown says he is hopeful that the London patient’s cure proves as durable as his own. “If something has happened once in medical science, it can happen again,” Mr. Brown said. “I’ve been waiting for company for a long time.”

This article was originally published in The New York Times. Read the original article.

An H.I.V. Cure: Answers to 4 Key Questions

At a scientific conference in Seattle on Tuesday, researchers reckoned with a day that many thought might never arrive. A patient appears to have been cured of H.I.V., the virus that causes AIDS, for only the second time since the epidemic began.

A sort of electric hope hangs in the air, said Dr. Steve Deeks, an AIDS specialist at the University of California, San Francisco, who is attending the gathering: “The whole approach to a cure is shifting more from aspiration to something that people are realizing could be feasible.”

It is a hope that must be tempered with realism: H.I.V. is a wily adversary, and scientists and patients living with the virus are all too well acquainted with past failures in the fight against the epidemic.

Here’s what the news means right now.

Not yet. The second case does provide “proof of concept,” shining a light on a potential path to an H.I.V. cure. Scientists intend to pursue it with vigor.

But this apparent success does not mean that an easy cure is around the corner, and certainly not that infected patients should stop taking their pills.

“Sometimes the amount of desperation for a cure is driven by the stigma that’s still out there,” said Richard Jefferys, a director at Treatment Action Group, an advocacy organization. “But while two or three people is a drop in the ocean compared to the 35 million H.I.V.-positive people in the world, it’s a whole lot better than zero.”

Both men believed to have been cured so far had H.I.V. and cancer. Both received bone-marrow transplants to treat the cancer, not the H.I.V. In each case, the bone-marrow donors carried a key genetic mutation, called delta 32, that hampers H.I.V.’s entry into certain blood cells.

Bone-marrow transplants are risky procedures, so this is not likely to be a treatment option for the majority of people with H.I.V. And it is worth noting that until now, most other attempts to repeat the first cure had also failed.

Whatever the path to a cure turns out to be, it will not be simple.

Cure means the virus seems to be gone forever. Remission is a more conservative term: The virus is under control in the body, but maybe not forever.

After his case, there were many failed attempts to duplicate this success. Each time, the virus came back after the patient stopped taking anti-H.I.V. drugs.

The newly reported case, in a man described only as the “London patient,” has been H.I.V.-free for 18 months since stopping the drugs. Extraordinarily sensitive tests cannot find the virus in his body. To some scientists, that’s a cure. Others are more skeptical.

“We don’t have any international agreement on what time without viral rebound is necessary to speak about cure,” said Dr. Annemarie Wensing, a virologist at the University Medical Center Utrecht in the Netherlands.

It is worth noting that there have been patients who went into remission without a bone-marrow transplant. In these cases, the immune system seems able to maintain tight control over the virus, even without drugs. For years, researchers have been trying to figure out how it happens.

A transplant from a delta 32 donor essentially wipes out the immune cells that are vulnerable to H.I.V., replacing them with cells that are resistant to the virus. Already many groups of scientists are trying to mimic the benefits of a bone-marrow transplant without the risks of the actual procedure.

The delta 32 mutation occurs in a gene that directs production of a protein called CCR5, which sits on the surface of certain immune cells. A common type of H.I.V. needs this protein, among others, to enter cells in order to reproduce.

The gene that directs production of CCR5 may be modified with newer gene therapy techniques, similar to treatments developed for hemophilia and sickle-cell disease. And scientists have tried to edit CCR5 from a person’s immune cells in the lab and to infuse the modified cells back into the body.

But so far the numbers of cells derived with this method do not seem to be enough to make anyone resistant to H.I.V.

In one trial funded by Sangamo Therapeutics, however, researchers reported a curious finding: Although the infusion did not cure H.I.V. infection, the amount of virus in the body seemed to decline by a thousandfold. The company is planning a follow-up study to explore this further.

Another approach would be to deliver enzymes that edit the genes directly into the body. The real challenge is in targeting the enzymes: Many teams are looking into delivery via nanoparticles, for example, but this strategy is years from success, Dr. Deeks said.

An even more intriguing option is to design a predecessor stem cell that would produce a steady stream of H.I.V.-resistant immune cells in the body. At least one group in China is trying to edit CCR5 from stem cells that can be infused into patients with both cancer and H.I.V.

Early studies at the University of Pennsylvania suggest that something like this might work, noted Dr. Mike McCune, a global health adviser to the Bill and Melinda Gates Foundation.

In addition, some scientists are trying to force the virus into remission with broadly neutralizing antibodies, immune molecules that can disable various types of H.I.V.

Five to 10 years at the earliest. And that covers only types of H.I.V. that rely on CCR5 to infect cells. Another form of H.I.V., called X4, relies on a different protein to enter cells; none of these theoretical treatments would guard against infection with that form of the virus.

“Nobody should really be anticipating a cure or a remission is around the corner,” Dr. McCune said.

But gene therapy and gene editing are moving at a lightning pace, and it is not unreasonable to think that some researcher somewhere will find a way to do for the immune system what these bone-marrow transplants did for these two patients.

“We need to push on multiple fronts at once,” Dr. McCune said.

 

This article was originally published in The New York Times. Read the original article.

A second person has probably been cured of HIV

ESTABLISHED HIV infection is easy to control but impossible to cure. Or almost impossible. The exception seems to be Timothy Brown, a man often referred to as the Berlin patient. In 2006, after a decade of successfully suppressing his infection with anti-retroviral drugs, Mr Brown developed an unrelated blood cancer, acute myeloid leukaemia. To treat this life-threatening condition he opted, the following year, for a blood-stem-cell transplant. And, at the same time, he volunteered as a guinea pig for an experimental anti-HIV treatment, which worked. Now, a team of doctors in London have reported a similar case.

Blood-stem-cell transplantation is a normal, though radical, treatment for various sorts of blood cancer. Stem cells are the precursors from which particular tissues grow. Blood-stem-cell transplantation involves using drugs (backed up, in Mr Brown’s case, by radiotherapy) to kill a patient’s natural blood-producing tissue, the bone marrow, and then transfusing in new stem cells from a donor.

So far, so normal. But Mr Brown, at the suggestion of his doctors, chose from among the 267 possible tissue-matched donors one who had inherited from both parents a mutation that, in healthy people, prevents HIV infection in the first place. (The mutation in question alters one of the proteins the virus attaches itself to when entering a cell.) After two such transplants Mr Brown was cleared of the leukaemia and, as far as it is possible to tell, HIV had stopped replicating in his body.

The newly reported patient, treated by Ravindra Gupta of University College, London, and his colleagues, had Hodgkin’s lymphoma and underwent a stem-cell transplant for this in 2016. As in Mr Brown’s case, the cell donor had inherited the protective mutation from both parents. Sixteen months later, as they describe in Nature, the patient’s doctors withdrew the HIV-controlling drugs and watched. There was no resurgence of the virus, as would be usual if those drugs were withdrawn from any other HIV patient. Nor has there been any change in the patient’s HIV status in the 18 months since the drugs’ withdrawal.

In cases like this doctors are loth to use the word “cured”, since the future is unpredictable and the mechanism involved serves only to break HIV’s reproductive chain, not to purge the virus from the body entirely. They talk instead of patients being “in remission”. Nevertheless, the experience of the person who will probably come to be known as the London patient is important. It shows Mr Brown’s case was not a fluke. Which gives comfort to those working on the idea of editing protective mutations into stem cells drawn from people with HIV, and then returning the edited cells to the patient. This would avoid the risks of rejection that come with transplants from donors.

Most researchers in the field are proceeding cautiously, testing their results on mice, and with some success. But this is an area that can encourage over-reach. The gene-edited-baby scandal which happened in China late last year was, according to those involved, an attempt to engineer the relevant mutation into people from birth.

Such over-reach aside, even if the editing of blood stem cells could be made to work reliably, transplanting them back into people would probably remain a rare procedure—for the methods used to kill a patient’s existing bone marrow make such transplantation dangerous in and of itself. But it would at least be available as a treatment of last resort for those with forms of HIV that have developed resistance to drugs. And that would save some lives.

 

This article was originally published in The Economist. Read the original article.

F.D.A. Panel Recommends New Depression Treatment

In a move that may clear the way for the first new treatment in years for depression, an expert panel recommended on Tuesday that federal regulators approve a nasal spray that delivers the active ingredients of ketamine, a popular club drug in the 1980s and 1990s.

The new drug, called Esketamine and developed by Johnson & Johnson, is aimed at people with severe depression, particularly those with suicidal thinking. The panel, with 17 voting members, including psychiatrists and consumer representatives, was nearly unanimous in deciding that the drug’s benefits outweighed its risks. The Food and Drug Administration typically follows the recommendations of its expert panels.

In recent years, scores of clinics have opened around the country, offering to administer intravenous ketamine for depression, on a schedule similar to that of electroshock therapy: as a series of treatments, over a period of days or weeks, and sometimes including follow-up or “booster” visits months later. These treatments, at an average cost of $3,000, are officially “off-label,” and usually are not covered by insurance. Their effectiveness is not well studied, although people who have received the course of treatment have reported rapid, if not always lasting, relief.

If approved, Esketamine would be covered by most insurers.

The interest in ketamine as a potential treatment dates back to 2006, when researchers at the National Institute of Mental Health, led by Dr. Carlos A. Zarate, reported that 18 people who received the drugs intravenously reported that their despair lifted within hours. The drugs currently on the market for depression typically take two weeks or more to provide any noticeable relief, if they do so at all.

The discovery of ketamine’s effects on depression was serendipitous; the underlying biology of the disorder remains unknown. Some researchers have since turned away from investigating serotonin — the brain transmitter on which most popular antidepressants work — to instead study the effect of ketamine on brain chemistry, to see if the drug provides any clues to the biology of depression.

The federal agency has until March 4 to decide whether to approve the drug.

Brook Johnson, 38, a piano teacher in Westminster, Md., has been waiting on approval for months. Ms. Johnson, who is married and has a 9-year-old daughter, doesn’t know if Esketamine will help her, but said that existing antidepressants have failed. She said she had been in and out of psychiatric hospitals six times and has attempted suicide twice.

“It was back and forth, and then I’d relapse and they’d put me back in,” Ms. Johnson said in an interview last month. “None of the medicines ever seemed to work. At best, they would either numb me out completely, and you just feel nothing and you can’t think.”

“I need alternative treatment as soon as possible,” she said.

 

This article was originally published in The New York Times. Read the original article.