COVID-19 & Antibodies

Before jumping into the specific relationship between antibodies and the novel coronavirus, let me explain the basics of antibody response from what I have learned in class. As soon as B cells are activated by an antigen, they produce plasma cells, which will produce antibodies. In the very beginning, before they know a whole lot about the invader, these plasma cells just start to produce IgM antibodies. Therefore, someone who has high levels of IgM coronavirus antibodies is at the beginning of their infections. Once a plasma cell begins to go through class switching, it will begin to produce IgG antibodies, which will be better at fighting against viruses. A patient with both IgM and IgG antibodies is in the process of fighting off the disease, but they have not completely cleared out the infection. A patient who only has IgG antibodies already fought off the infection and is prepared to eliminate the antigen if it came back into contact with it. These people would be less likely to infect others.

              However, scientists are still researching the novel coronavirus to figure out how it will be effected by antibodies, and this article discusses many of the uncertainties that still need to be researched. We develop varying levels of immunity to different viruses after exposure, depending on several characteristics of each virus. If the virus behind COVID-19 behaves similarly to the coronaviruses that cause the common cold, then people will not gain lasting immunity after infection. If this is the case, it may not be safe for people with high levels of IgG to return to work or stop social distancing. On the other hand, if this coronavirus is similar to the one that causes SARS, people who were infected will develop immunity that lasts for a few years, and it would be safe for them to return to normal activities.             

  I found another article that explained the practical applications of an antibody test if one was able to be used after the aforementioned research was completed. Many people who are infected with the novel coronavirus remain asymptomatic, so these antibody tests would be the only way to know if they have been exposed and are now immune. This test would be useful to figure out which healthcare workers could safely go to work without risking their own health or the health of their patients. A healthcare worker (or any worker) who is asymptomatic but still has IgM antibodies should not interact with others because they could still spread the virus. National Institutes of Health is planning on testing 10,000 health volunteers to see if they can safely continue to work and risk being exposed.