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Will an Antibody Test Allow Us to Go Back to School or Work? Will an Antibody Test Allow Us to Go Back to School or Work?
(about 13 hours later)
When will life return to normal, or at least a new normal?When will life return to normal, or at least a new normal?
A major answer to the question of when — and how — Americans can return to public places like work and school could depend on something called an antibody test, a blood test that determines whether someone has ever been infected with the coronavirus.A major answer to the question of when — and how — Americans can return to public places like work and school could depend on something called an antibody test, a blood test that determines whether someone has ever been infected with the coronavirus.
People who are believed to be immune may be able to safely return to work. It would be especially important to know which health care workers are protected from getting infected and could continue to care for sick people.People who are believed to be immune may be able to safely return to work. It would be especially important to know which health care workers are protected from getting infected and could continue to care for sick people.
The Centers for Disease Control and Prevention recently announced that it would begin using antibody tests to see what proportion of the population has already been infected. On Friday, the National Institutes of Health announced it would test 10,000 healthy volunteers around the country for the presence of antibodies.The Centers for Disease Control and Prevention recently announced that it would begin using antibody tests to see what proportion of the population has already been infected. On Friday, the National Institutes of Health announced it would test 10,000 healthy volunteers around the country for the presence of antibodies.
“Within a period of a week or so, we are going to have a rather large number of tests that are available,” Dr. Anthony S. Fauci, the leading infectious disease expert in the U.S., said Friday morning on CNN.“Within a period of a week or so, we are going to have a rather large number of tests that are available,” Dr. Anthony S. Fauci, the leading infectious disease expert in the U.S., said Friday morning on CNN.
He said the White House coronavirus task force was discussing the idea of “certificates of immunity,” which could be issued to people who had previously been infected.He said the White House coronavirus task force was discussing the idea of “certificates of immunity,” which could be issued to people who had previously been infected.
“As we get to the point of considering opening the country,” Dr. Fauci said, “it is very important to understand how much that virus has penetrated society.” Immunity certificates, he said, had “some merit under certain circumstances.”“As we get to the point of considering opening the country,” Dr. Fauci said, “it is very important to understand how much that virus has penetrated society.” Immunity certificates, he said, had “some merit under certain circumstances.”
The idea of providing proof of immunity to allow workers to return to their jobs is being considered in many countries, including Britain and Italy. But as with any test, they are not perfect, and there have been problems with their accuracy.The idea of providing proof of immunity to allow workers to return to their jobs is being considered in many countries, including Britain and Italy. But as with any test, they are not perfect, and there have been problems with their accuracy.
Here’s what we know — and don’t know — about these tests.Here’s what we know — and don’t know — about these tests.
What exactly is a serology test?What exactly is a serology test?
A serology test looks for signs of an immune response — in this case, to the new coronavirus.A serology test looks for signs of an immune response — in this case, to the new coronavirus.
When your body encounters a virus, it takes some time for it to recognize the invader and to begin to scale up an immune response. Immune molecules called antibodies are a crucial part of this response.When your body encounters a virus, it takes some time for it to recognize the invader and to begin to scale up an immune response. Immune molecules called antibodies are a crucial part of this response.
The first type of antibody to appear is called immunoglobulin M or IgM, and its levels spike within a few days of infection. But IgM is a generic fighter. To target and destroy a specific virus, the body refines it into a second type of antibody, called immunoglobulin G, or IgG, that can recognize that virus.The first type of antibody to appear is called immunoglobulin M or IgM, and its levels spike within a few days of infection. But IgM is a generic fighter. To target and destroy a specific virus, the body refines it into a second type of antibody, called immunoglobulin G, or IgG, that can recognize that virus.
As IgG levels rise, IgM levels drop; IgG levels peak around 28 days after the onset of infection.As IgG levels rise, IgM levels drop; IgG levels peak around 28 days after the onset of infection.
There is a third type of antibody, called IgA, that is present in mucosal tissues — like the inner lining of the lung. IgA is known to be important for fighting respiratory infections such as influenza, and is likely to be central in coronavirus infection, too.There is a third type of antibody, called IgA, that is present in mucosal tissues — like the inner lining of the lung. IgA is known to be important for fighting respiratory infections such as influenza, and is likely to be central in coronavirus infection, too.
Many of the tests being developed look for levels of all three antibodies; some look for just IgM and IgG, and still others test for only one type.Many of the tests being developed look for levels of all three antibodies; some look for just IgM and IgG, and still others test for only one type.
What can these tests tell us? And what can’t they?What can these tests tell us? And what can’t they?
Let’s begin with what they can’t tell us. Because the antibodies come up so late, these tests are not helpful for diagnosing an early infection. “For that they are useless,” said Dr. Florian Krammer, a virologist at the Icahn School of Medicine at Mount Sinai in New York.Let’s begin with what they can’t tell us. Because the antibodies come up so late, these tests are not helpful for diagnosing an early infection. “For that they are useless,” said Dr. Florian Krammer, a virologist at the Icahn School of Medicine at Mount Sinai in New York.
The tests are more effective at detecting the presence of antibody responses across large numbers of people, not just to determine who is immune but how widely the virus has spread in the population.The tests are more effective at detecting the presence of antibody responses across large numbers of people, not just to determine who is immune but how widely the virus has spread in the population.
From 25 to 50 percent of people who become infected may never develop symptoms, and some may become only mildly ill. Others may have known they were sick, but could not get tested. Serology tests would be able to identify these people and help scientists better estimate the death rate of Covid-19, the disease caused by the virus.From 25 to 50 percent of people who become infected may never develop symptoms, and some may become only mildly ill. Others may have known they were sick, but could not get tested. Serology tests would be able to identify these people and help scientists better estimate the death rate of Covid-19, the disease caused by the virus.
“We don’t currently have good numbers for the numbers of people who are infected now, much less people who were infected before who were never tested,” said Dr. Angela Rasmussen, a virologist at Columbia University in New York. “So it’s really important from an epidemiological perspective to do these types of serology assays.”“We don’t currently have good numbers for the numbers of people who are infected now, much less people who were infected before who were never tested,” said Dr. Angela Rasmussen, a virologist at Columbia University in New York. “So it’s really important from an epidemiological perspective to do these types of serology assays.”
Governments around the world are also hopeful that serology tests can tell them which people are protected from re-infection and can safely go back to work. Knowing the full scope of the pandemic would help them decide when to end social isolation measures and allow businesses and schools to reopen.Governments around the world are also hopeful that serology tests can tell them which people are protected from re-infection and can safely go back to work. Knowing the full scope of the pandemic would help them decide when to end social isolation measures and allow businesses and schools to reopen.
Tracking the rise and fall of antibody levels may also enable scientists to back-calculate the dates of infection, and help them predict whether the virus shows seasonal fluctuations.Tracking the rise and fall of antibody levels may also enable scientists to back-calculate the dates of infection, and help them predict whether the virus shows seasonal fluctuations.
I’m pretty sure I had the coronavirus already. Can I take a test and go back to work?I’m pretty sure I had the coronavirus already. Can I take a test and go back to work?
Not yet. Most of the tests being developed offer a simple yes-no answer to the question of who has antibodies, and who was exposed to the virus. But simply having antibodies is no guarantee of immunity.Not yet. Most of the tests being developed offer a simple yes-no answer to the question of who has antibodies, and who was exposed to the virus. But simply having antibodies is no guarantee of immunity.
“Being immune means that if you’re exposed to the virus, your immune system will clear the virus out before it can establish a productive infection,” Dr. Rasmussen said.“Being immune means that if you’re exposed to the virus, your immune system will clear the virus out before it can establish a productive infection,” Dr. Rasmussen said.
Some people — because they had mild or no symptoms, for example — might have developed antibodies that are too weak to prevent re-infection. Conversely, others who have low levels of IgG may still be protected.Some people — because they had mild or no symptoms, for example — might have developed antibodies that are too weak to prevent re-infection. Conversely, others who have low levels of IgG may still be protected.
That’s because antibodies are just one well-understood piece of the immune response. Immune cells called T-cells may also be involved. “A lot less is known about how these different parts of the immune system work together to provide protective immunity,” Dr. Rasmussen said.
Updated June 22, 2020Updated June 22, 2020
A commentary published this month on the website of the British Journal of Sports Medicine points out that covering your face during exercise “comes with issues of potential breathing restriction and discomfort” and requires “balancing benefits versus possible adverse events.” Masks do alter exercise, says Cedric X. Bryant, the president and chief science officer of the American Council on Exercise, a nonprofit organization that funds exercise research and certifies fitness professionals. “In my personal experience,” he says, “heart rates are higher at the same relative intensity when you wear a mask.” Some people also could experience lightheadedness during familiar workouts while masked, says Len Kravitz, a professor of exercise science at the University of New Mexico.A commentary published this month on the website of the British Journal of Sports Medicine points out that covering your face during exercise “comes with issues of potential breathing restriction and discomfort” and requires “balancing benefits versus possible adverse events.” Masks do alter exercise, says Cedric X. Bryant, the president and chief science officer of the American Council on Exercise, a nonprofit organization that funds exercise research and certifies fitness professionals. “In my personal experience,” he says, “heart rates are higher at the same relative intensity when you wear a mask.” Some people also could experience lightheadedness during familiar workouts while masked, says Len Kravitz, a professor of exercise science at the University of New Mexico.
The steroid, dexamethasone, is the first treatment shown to reduce mortality in severely ill patients, according to scientists in Britain. The drug appears to reduce inflammation caused by the immune system, protecting the tissues. In the study, dexamethasone reduced deaths of patients on ventilators by one-third, and deaths of patients on oxygen by one-fifth.The steroid, dexamethasone, is the first treatment shown to reduce mortality in severely ill patients, according to scientists in Britain. The drug appears to reduce inflammation caused by the immune system, protecting the tissues. In the study, dexamethasone reduced deaths of patients on ventilators by one-third, and deaths of patients on oxygen by one-fifth.
The coronavirus emergency relief package gives many American workers paid leave if they need to take time off because of the virus. It gives qualified workers two weeks of paid sick leave if they are ill, quarantined or seeking diagnosis or preventive care for coronavirus, or if they are caring for sick family members. It gives 12 weeks of paid leave to people caring for children whose schools are closed or whose child care provider is unavailable because of the coronavirus. It is the first time the United States has had widespread federally mandated paid leave, and includes people who don’t typically get such benefits, like part-time and gig economy workers. But the measure excludes at least half of private-sector workers, including those at the country’s largest employers, and gives small employers significant leeway to deny leave.The coronavirus emergency relief package gives many American workers paid leave if they need to take time off because of the virus. It gives qualified workers two weeks of paid sick leave if they are ill, quarantined or seeking diagnosis or preventive care for coronavirus, or if they are caring for sick family members. It gives 12 weeks of paid leave to people caring for children whose schools are closed or whose child care provider is unavailable because of the coronavirus. It is the first time the United States has had widespread federally mandated paid leave, and includes people who don’t typically get such benefits, like part-time and gig economy workers. But the measure excludes at least half of private-sector workers, including those at the country’s largest employers, and gives small employers significant leeway to deny leave.
So far, the evidence seems to show it does. A widely cited paper published in April suggests that people are most infectious about two days before the onset of coronavirus symptoms and estimated that 44 percent of new infections were a result of transmission from people who were not yet showing symptoms. Recently, a top expert at the World Health Organization stated that transmission of the coronavirus by people who did not have symptoms was “very rare,” but she later walked back that statement.So far, the evidence seems to show it does. A widely cited paper published in April suggests that people are most infectious about two days before the onset of coronavirus symptoms and estimated that 44 percent of new infections were a result of transmission from people who were not yet showing symptoms. Recently, a top expert at the World Health Organization stated that transmission of the coronavirus by people who did not have symptoms was “very rare,” but she later walked back that statement.
Touching contaminated objects and then infecting ourselves with the germs is not typically how the virus spreads. But it can happen. A number of studies of flu, rhinovirus, coronavirus and other microbes have shown that respiratory illnesses, including the new coronavirus, can spread by touching contaminated surfaces, particularly in places like day care centers, offices and hospitals. But a long chain of events has to happen for the disease to spread that way. The best way to protect yourself from coronavirus — whether it’s surface transmission or close human contact — is still social distancing, washing your hands, not touching your face and wearing masks.Touching contaminated objects and then infecting ourselves with the germs is not typically how the virus spreads. But it can happen. A number of studies of flu, rhinovirus, coronavirus and other microbes have shown that respiratory illnesses, including the new coronavirus, can spread by touching contaminated surfaces, particularly in places like day care centers, offices and hospitals. But a long chain of events has to happen for the disease to spread that way. The best way to protect yourself from coronavirus — whether it’s surface transmission or close human contact — is still social distancing, washing your hands, not touching your face and wearing masks.
A study by European scientists is the first to document a strong statistical link between genetic variations and Covid-19, the illness caused by the coronavirus. Having Type A blood was linked to a 50 percent increase in the likelihood that a patient would need to get oxygen or to go on a ventilator, according to the new study.A study by European scientists is the first to document a strong statistical link between genetic variations and Covid-19, the illness caused by the coronavirus. Having Type A blood was linked to a 50 percent increase in the likelihood that a patient would need to get oxygen or to go on a ventilator, according to the new study.
The unemployment rate fell to 13.3 percent in May, the Labor Department said on June 5, an unexpected improvement in the nation’s job market as hiring rebounded faster than economists expected. Economists had forecast the unemployment rate to increase to as much as 20 percent, after it hit 14.7 percent in April, which was the highest since the government began keeping official statistics after World War II. But the unemployment rate dipped instead, with employers adding 2.5 million jobs, after more than 20 million jobs were lost in April.The unemployment rate fell to 13.3 percent in May, the Labor Department said on June 5, an unexpected improvement in the nation’s job market as hiring rebounded faster than economists expected. Economists had forecast the unemployment rate to increase to as much as 20 percent, after it hit 14.7 percent in April, which was the highest since the government began keeping official statistics after World War II. But the unemployment rate dipped instead, with employers adding 2.5 million jobs, after more than 20 million jobs were lost in April.
States are reopening bit by bit. This means that more public spaces are available for use and more and more businesses are being allowed to open again. The federal government is largely leaving the decision up to states, and some state leaders are leaving the decision up to local authorities. Even if you aren’t being told to stay at home, it’s still a good idea to limit trips outside and your interaction with other people.States are reopening bit by bit. This means that more public spaces are available for use and more and more businesses are being allowed to open again. The federal government is largely leaving the decision up to states, and some state leaders are leaving the decision up to local authorities. Even if you aren’t being told to stay at home, it’s still a good idea to limit trips outside and your interaction with other people.
Common symptoms include fever, a dry cough, fatigue and difficulty breathing or shortness of breath. Some of these symptoms overlap with those of the flu, making detection difficult, but runny noses and stuffy sinuses are less common. The C.D.C. has also added chills, muscle pain, sore throat, headache and a new loss of the sense of taste or smell as symptoms to look out for. Most people fall ill five to seven days after exposure, but symptoms may appear in as few as two days or as many as 14 days.Common symptoms include fever, a dry cough, fatigue and difficulty breathing or shortness of breath. Some of these symptoms overlap with those of the flu, making detection difficult, but runny noses and stuffy sinuses are less common. The C.D.C. has also added chills, muscle pain, sore throat, headache and a new loss of the sense of taste or smell as symptoms to look out for. Most people fall ill five to seven days after exposure, but symptoms may appear in as few as two days or as many as 14 days.
If air travel is unavoidable, there are some steps you can take to protect yourself. Most important: Wash your hands often, and stop touching your face. If possible, choose a window seat. A study from Emory University found that during flu season, the safest place to sit on a plane is by a window, as people sitting in window seats had less contact with potentially sick people. Disinfect hard surfaces. When you get to your seat and your hands are clean, use disinfecting wipes to clean the hard surfaces at your seat like the head and arm rest, the seatbelt buckle, the remote, screen, seat back pocket and the tray table. If the seat is hard and nonporous or leather or pleather, you can wipe that down, too. (Using wipes on upholstered seats could lead to a wet seat and spreading of germs rather than killing them.)If air travel is unavoidable, there are some steps you can take to protect yourself. Most important: Wash your hands often, and stop touching your face. If possible, choose a window seat. A study from Emory University found that during flu season, the safest place to sit on a plane is by a window, as people sitting in window seats had less contact with potentially sick people. Disinfect hard surfaces. When you get to your seat and your hands are clean, use disinfecting wipes to clean the hard surfaces at your seat like the head and arm rest, the seatbelt buckle, the remote, screen, seat back pocket and the tray table. If the seat is hard and nonporous or leather or pleather, you can wipe that down, too. (Using wipes on upholstered seats could lead to a wet seat and spreading of germs rather than killing them.)
If you’ve been exposed to the coronavirus or think you have, and have a fever or symptoms like a cough or difficulty breathing, call a doctor. They should give you advice on whether you should be tested, how to get tested, and how to seek medical treatment without potentially infecting or exposing others.If you’ve been exposed to the coronavirus or think you have, and have a fever or symptoms like a cough or difficulty breathing, call a doctor. They should give you advice on whether you should be tested, how to get tested, and how to seek medical treatment without potentially infecting or exposing others.
If you’re sick and you think you’ve been exposed to the new coronavirus, the C.D.C. recommends that you call your healthcare provider and explain your symptoms and fears. They will decide if you need to be tested. Keep in mind that there’s a chance — because of a lack of testing kits or because you’re asymptomatic, for instance — you won’t be able to get tested.If you’re sick and you think you’ve been exposed to the new coronavirus, the C.D.C. recommends that you call your healthcare provider and explain your symptoms and fears. They will decide if you need to be tested. Keep in mind that there’s a chance — because of a lack of testing kits or because you’re asymptomatic, for instance — you won’t be able to get tested.
That’s because antibodies are just one well-understood piece of the immune response. Immune cells called T-cells may also be involved. “A lot less is known about how these different parts of the immune system work together to provide protective immunity,” Dr. Rasmussen said.
Some tests, like one developed by Dr. Krammer, offer not just a yes-no answer, but a clearer picture of the antibodies’ ability to neutralize the virus.Some tests, like one developed by Dr. Krammer, offer not just a yes-no answer, but a clearer picture of the antibodies’ ability to neutralize the virus.
Plasma from people who have strong antibodies is being used to treat people who are unable to mount an immune response.Plasma from people who have strong antibodies is being used to treat people who are unable to mount an immune response.
When will serology tests be widely available?When will serology tests be widely available?
Some are already available and being used, but it’s the early days and it’s unclear how good they are. Last week, the Food and Drug Administration granted an emergency use authorization to one such test. But others are being used in research projects and by hospitals.Some are already available and being used, but it’s the early days and it’s unclear how good they are. Last week, the Food and Drug Administration granted an emergency use authorization to one such test. But others are being used in research projects and by hospitals.
In March, the F.D.A. allowed developers to begin to sell or use antibody tests without first getting the agency’s permission, once the companies had done their own evaluations to ensure the tests were accurate and reliable. Since then, more than 70 test developers have notified the agency that they have serological tests available. But the agency said some companies have falsely claimed that their tests were F.D.A.-approved, or falsely claimed they could diagnose Covid-19.In March, the F.D.A. allowed developers to begin to sell or use antibody tests without first getting the agency’s permission, once the companies had done their own evaluations to ensure the tests were accurate and reliable. Since then, more than 70 test developers have notified the agency that they have serological tests available. But the agency said some companies have falsely claimed that their tests were F.D.A.-approved, or falsely claimed they could diagnose Covid-19.
The C.D.C.’s project is one of dozens. The World Health Organization is also planning to test large numbers of people in multiple countries. Some universities, townships and countries have begun testing on their own as well.The C.D.C.’s project is one of dozens. The World Health Organization is also planning to test large numbers of people in multiple countries. Some universities, townships and countries have begun testing on their own as well.
But “serological tests are plagued with issues,” Dr. Rasmussen said, and problems are surfacing even as these tests proceed.But “serological tests are plagued with issues,” Dr. Rasmussen said, and problems are surfacing even as these tests proceed.
In the U.K., for example, the tests are plagued with false negatives (not picking up antibodies when they’re present) and with false positives (indicating antibodies when there are none). Some of the tests may not be specific enough to the new coronavirus; they may pick up a signal from antibodies made in response to infections with the coronaviruses that cause common colds.In the U.K., for example, the tests are plagued with false negatives (not picking up antibodies when they’re present) and with false positives (indicating antibodies when there are none). Some of the tests may not be specific enough to the new coronavirus; they may pick up a signal from antibodies made in response to infections with the coronaviruses that cause common colds.
False positives, in particular, are dangerous because they can lull people into believing they are immune when they are not, and becoming exposed to the virus. “Certainly if somebody thinks that they’re protected and they’re not, that would be a problem,” Dr. Rasmussen said.False positives, in particular, are dangerous because they can lull people into believing they are immune when they are not, and becoming exposed to the virus. “Certainly if somebody thinks that they’re protected and they’re not, that would be a problem,” Dr. Rasmussen said.
If someone is immune to the virus, how long will the immunity last?If someone is immune to the virus, how long will the immunity last?
We don’t know.We don’t know.
This is a new virus, and so we have no way of knowing exactly how long immunity to the virus will last. Our best guess comes from looking at its cousins, the common cold coronaviruses, as well as the more dangerous ones that caused SARS and MERS. Immunity to these viruses persists anywhere from one to eight years.This is a new virus, and so we have no way of knowing exactly how long immunity to the virus will last. Our best guess comes from looking at its cousins, the common cold coronaviruses, as well as the more dangerous ones that caused SARS and MERS. Immunity to these viruses persists anywhere from one to eight years.
The best way to find out, Dr. Krammer said, is to follow people with and without the antibodies and see when they might become reinfected. “Those are the studies that are now needed,” he said. “They will take time.”The best way to find out, Dr. Krammer said, is to follow people with and without the antibodies and see when they might become reinfected. “Those are the studies that are now needed,” he said. “They will take time.”