So, for certain viral infections in some people the immune response that develops may give protection from reinfection, but for some people/viruses not so much. Further complicating all this is the fact that viral mutations can possibly make an end-run around any immune response. The bad news is that we know that reinfection with COVID-19 is common; that is, prior infection with COVID-19 gives at best a partial immunity. This study definitively showed that people who had already been infected with COVID-19 were over twice as likely to be reinfected if they did not get vaccinated. The bottom line is that even people who have already been infected and then recovered from COVID-19 should be vaccinated.

Source: MetroXpress August 16, 2021 14:26 UTC