Recent research is starting to shed light on the course of antibody response to Covid-19. According to the research, antibody response to Covid-19 really starts increase exponentially. In fact, on average, by about 9-10 days following onset of signs and symptoms of Covid-19, there was an increase of four fold of IgM and IgG . The typical course of antibodies for Covid is similar to SARs. In patients shortly following signs and symptoms of Covid-19, very low titres exist of either IgM or IgG, but they are mainly IgM. This makes sense, since mainly concentration of IgM would signify that someone has been recently infected with Covid-19. In addition, the data suggests that the median time of class switching of for IgM to IgG is 14 days. Therefore, having higher concentrations of IgM and IgG suggest that someone is further along in the disease progress of Covid-19. I think efficient and rapid testing of IgM and IgG antibodies could play a big role in public health policy in order to identify potential asymptomatic carriers. This would in turn limit the spread of Covid-19 and allow people to social distance when restrictions are ultimately lifted.
In fact, other research looking into a combined IgG and IgM test out of China that identifies a prompt antibody response to Covid-19. In fact, standard testing primarily uses nucleic acid PCR test kits, while this test is an immunoassay that detects IgM and IgG. The primary benefit of this test is that detecting levels of IgG and IgM are able to deduce who is an asymptomatic carrier. Because Covid-19 starts in the lungs, PCR tests can sometimes provide false negatives. However, tracking antibody response through IgG and IgM would be able to identify who is asymptomatic and potentially spreading the virus. I think finding tests that specifically target who is an asymptomatic carrier is vitally important. This is because I think that Covid-19, in particular, is very contagious with a fairly high R naught value. Therefore, early and fast testing is extremely important and will be important to enhance social distancing measures to mitigates the spread of the virus.
Finally, the research that tracked the antibody response of patients infected with Covid-19 provides insight on the importance of identifying people with high concentrations of IgG titres. For example, in this study, following day 20 of infection with Covid-19, IgG titres rose to 1,280 and was the primary antibody present. Individuals with high levels of only IgG antibodies would demonstrate that they have been infected with Covid in the past. This information could be essential in understanding those who may have some immunity to Covid, as well as those who could provide serum antibodies for protection for those who are immunocompromised and need the antibodies. Therefore, I find it quite promising that research into the antibody response to Covid-19 may be the first step in determining effective therapy for the immunocompromised populations. This is certainly relevant because it is this population that we need to protect from Covid-19 as soon as possible. Overall, I think that finding the most efficient, sensitive, and specific will continue to be vital , especially in the short term, to mitigate the incidence of Covid-19 in the future.
Infectious Disease 