The CDC has released new guidance stating the results of antibody tests are wrong half the time. The agency also said that antibody tests shouldn't be used to make important decisions about re-opening.
The Food and Drug Administration has also said that antibody tests are not reliable.
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The CDC has released new guidance on antibody tests, warning that they can be wrong half the time and shouldn't be used to inform important policy decisions. The antibody test, also known as a serologic test, is a blood test that checks the body to see if it has antibodies that can fight COVID-19, and can help people figure out if they had COVID-19 and recovered. The immune system creates antibodies to fight disease, and often these antibodies remain in the body after recovery, and can be donated to people currently fighting coronavirus. But this medical test is often inaccurate. Sometimes the test can result in a false positive, wrongly suggesting a patient does have coronavirus-fighting antibodies, or a false negative. "Serologic test results should not be used to make decisions about grouping persons residing in or being admitted to congregate settings, such as schools, dormitories, or correctional facilities," it says on the CDC website. "Serologic test results should not be used to make decisions about returning persons to the workplace." Previously, employers had been considering relying on these tests to determine when people could head back into workplaces, while hundreds of companies rushed to create their own version of the tests and hospitals offered these tests to healthcare workers, children, and anyone who wanted them. But even when these often-unreliable tests gave people a positive result, that wasn't something that carried any weight during a pandemic. "Even when you log on to your healthcare portal, and it says, 'Congratulations, you are positive for Covid antibodies,' meaning you ostensibly have some immunity, it's not like something you can take to the bank," Dr. Andrew Noymer, a public health associate professor at the University of California Irvine, previously told Insider. There is still a lot researchers don't understand about COVID-19 and antibodies Molly DeMellier, a 27-year-old girl who survived COVID-19, tried to donate blood to the Mount Sinai antibody trial. She assumed that since she survived the novel coronavirus, her body had produced antibodies that she could donate for other people sick with the disease. At Mount Sinai, she discovered she barely had enough antibodies to donate, raising more questions about the nature of antibodies and their possible use, Insider's Julia Naftulin previously reported. "As with anything else in medicine, that there is probably a variable response that people's bodies have to this virus," Dr. David L. Reich, President and Chief Operating Officer of Mount Sinai, previously told Insider. "And it's unclear if it has anything to do with severity of disease or other factors because it's just way too soon in the history of this disease to have figured that out." Millions of antibody tests, produced by hundreds of companies, are flooding the American market. The FDA, which originally rushed to approve antibody tests, implemented a tougher testing system on May 4 after the accuracy of those tests were called into question. "It's a disaster. These tests are not worth anything, or have very little use," one CEO said, according to a recording provided to Business Insider by the company. Join the conversation about this story » NOW WATCH: How the Navy's largest hospital ship can help with the coronavirus
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CDC clarifies that science does not imply people are immune to coronavirus in the 3 months after infection
The US Centers for Disease Control and Prevention recently updated its coronavirus quarantine guidelines to make...The US Centers for Disease Control and Prevention recently updated its coronavirus quarantine guidelines to make an exception for people who have had the virus in the last three months. The CDC released a statement on Friday clarifying that it was not saying those people have immunity against reinfection — instead, they're less likely to be infectious. Growing research shows that people who recover from COVID-19 develop some immunity, but experts don't yet know how long that lasts. Visit Business Insider's homepage for more stories. The human body's immune response to the coronavirus remains a mystery, even in the months immediately following infection. It's still unclear how long people who recover from the virus are immune to reinfection. Research on the subject is so inconclusive that the CDC has hesitated to define that time period. The agency seemed to do that for the first time in early August when it updated its quarantine guidelines to exclude people who have had the virus in the last three months. But on Friday the CDC issued a statement clarifying that it was not saying those people have immunity. "On August 3, 2020, CDC updated its isolation guidance based on the latest science about COVID-19 showing that people can continue to test positive for up to three months after diagnosis and not be infectious to others," read a statement the agency issued on Friday. "Contrary to media reporting today, this science does not imply a person is immune to reinfection with SARS-CoV-2, the virus that causes COVID-19, in the three months following infection." The August 3 update had seemed to imply that people would probably be safe from reinfection for three months. Those guidelines say that people who have had COVID-19 in the last three months don't need to quarantine or get tested as long as they don't develop symptoms again — even if they have been in close contact with someone who has COVID-19, which seems to imply that they are not susceptible to reinfection. Instead, a CDC spokesperson told CNN, the new guidance was "based on the latest science about COVID-19 showing that people can continue to test positive for up to three months after diagnosis and not be infectious to others." People who recover from COVID-19 probably gain some immunity The Friday statement pointed to the results of 15 recent studies on how and when people can spread the virus. The research suggested that the amount of live virus in a person's nose and throat (which can then get into the air and spread to other people) drops significantly soon after they show symptoms. The science also shows that most people are infectious for no longer than 10 days after their first symptoms — 20 days for people who are severely ill or immunocompromised. Other research has shown that antibodies can disappear quickly after infection. But many experts believe that people who recover from the coronavirus do gain some immunity. That's because the immune response doesn't just come from antibodies. Other agents which don't show up in antibody tests mount an immune response to the virus if it re-enters the body. White blood cells can identify and kill infected cells, as well as create new antibodies to fight back the pathogen. Early research has shown that recovered patients do retain some of these white blood cells, which last much longer than the antibodies themselves. "There's a lot that we are still learning," Maria Van Kerkhove, an epidemiologist serving as the World Health Organization's technical lead on the coronavirus, said in a press briefing on Thursday. "We expect that individuals infected with the SARS-CoV-2 virus develop an immune response. We don't know for how long that immune response lasts. We don't know how strong it is."Join the conversation about this story » NOW WATCH: How billionaires got $637 billion richer during the coronavirus pandemic
Declining antibody levels do not mean less immunity, experts say. Besides, two widely used tests may...Declining antibody levels do not mean less immunity, experts say. Besides, two widely used tests may detect the wrong antibodies.
Men who have fought off virus have higher levels of antibodies in their blood than womenCoronavirus...Men who have fought off virus have higher levels of antibodies in their blood than womenCoronavirus – latest updatesSee all our coronavirus coverageMen who have recovered from Covid-19 are being asked to donate plasma to be used to treat sick patients in trials because they have higher levels of virus-fighting antibodies in their blood than women.Convalescent plasma is being trialled around the world as a possible treatment for the disease. It contains antibodies generated by the immune systems of people who have fought off the virus. Continue reading...