Scientists have identified the causes of re-infection of some coronavirus patients.
Specialists at Massachusetts General Hospital in the United States examined the spleen and lymph nodes of patients who died of COVID-19 and found that there were no germinal centers, which are an integral part of a sustained immune response. These centers are responsible for a stable immune response in which B cells, called immune cells, secrete antibodies.
These antibodies, which are familiar to the body, attack the virus and protect it from re-infection. However, as the disease progresses, a large number of signal molecules - the TNF cytokine - are secreted where germinal centers need to be formed. Scientists believe that there are two ways of immunity - vaccination or symptoms. Mild and asymptomatic transmission of the disease does not provide long-term protection against the virus. Experts have concluded that some people who recover from this condition may become infected with the coronavirus again in a few months.
In South Korea, scientists say that people who have been re-diagnosed with the coronavirus after recovery do not pose a threat to others. The test results of such people were called false positive.