An article from Vox describes how the CDC has begun using blood tests to check for coronavirus immunity. How does this work? Well, we all know that the use of nose swabs allows us to detect if a person is experiencing an active Covid-19 infection. But, a blood test will allow us to detect if a person had been exposed to the virus, even if they did not become symptomatic. We are able to do this by testing for certain types of antibodies. Antibodies are proteins that are made by our immune system that bind to antigen (like the coronavirus) to fight infection.
If an individual has these antibodies in their blood, that is a good indicator that they did in-fact come into contact with Covid-19 and they would have some immunity if they came into contact with the same virus again. Testing for people who have these protective antibodies is a good first step in releasing people from a strict “stay at home” order. This is unless the virus mutates, in which case, an individual’s protective antibodies will no longer recognize the virus and we are back at square one. If an individual had IgM (Ig=immunoglobulin: another word for antibody) antibody titers, it would most likely mean they are actively fighting an infection in their bloodstream. If an individual had high IgG titers, it would most likely mean that they were infected with Covid-19 but are probably no longer contagious, and now have long lasting immunity against the virus. IgG titers can also be indicative of a very late stage infection. Levels of IgG are even higher if the individual comes into contact with the same pathogen again, but their immune response will be much quicker and precise.
A Mass Device article discusses the significance of antibody tests during this pandemic. Antibody tests, also know as serology tests, are readily available unlike the current swabs needed to test for Covid-19. They are much more cost effective and can give accurate results in as little as fifteen minutes. This testing method is urged not to be used as the sole method of coronavirus detection but has been approved under the public health emergency guidance, even though FDA approval is still pending. The unique advantage of serology testing is the ability to differentiate between infected individuals, asymptomatic infected individuals, and individuals who are immune and safe to go about their daily lives. Hopefully the information gathered from these rapid antibody tests will help to “flatten the curve”!
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