Coronavirus continues to spread all over the world and the immune systems of people who are unfortunate enough to be infected are responding to this with antibodies. Antibodies are the weapon used by the B cells in acquired immune system to fight antigens that invade the body. Doctors are using antibody tests to determine whether people have COVID or have recovered from it. Determining whether or not a person is infected with COVID is important for many people looking to return to work/school. Some people are proposing a proof of immunity in order for people to be able to return to work and school. That way people can start going back to their normal daily lives without fear of contracting the virus or spreading it to others. I think this is great because testing for immunity will give people the peace of mind to return to normal living. The problem with this is still getting everyone to take the test, if everyone doesn’t take the test and infected people go back into the world then we are right back to where we started.
Antibody tests work by detecting the body’s immune response to the infection caused by the virus. This is different than the other COVID detection test, which is a swab that looks for the presence of the virus in the nose. IgM is the first antibody produced by the body in response to infection when B cells are partially activated, after B cells are fully activated by helper T cells they will secrete IgG antibodies. IgG antibodies are more effective and can perform more antibody functions than IgM. However, IgG takes some time to be produced by the body, so if only IgM antibodies are present that means a person is in the early stages of COVID infection. If a person has both IgM and IgG antibodies against COVID that means they are in the peak of infection and are very contagious. A person with only IgG antibodies has fought off the virus and developed memory B cells against the virus and is not contagious to others. I think this is a great way to test for immunity and infection at the same time, something the original test cannot do.
The goal of these tests is to determine the number of people who have been infected and determine who is immune. However, the test does have some potential problems. For one, if the antibody test is given in the first few days of infection there may be a false negative. This is because it takes a few days for any antibodies to be produced, so this limits the effectiveness of these tests. Another potential problem with this test is cross-reaction among antibodies. There are many types of coronaviruses and scientists still do not know if this will cause the tests to give false-positives or false-negatives. If these tests can be made available to everyone, using these tests in addition to the other COVID detection test would vastly decrease the number of coronavirus cases. That way, the government could mandate who is allowed to leave the house, limiting the number of people who could get infected.
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