Given the data we already have on the mechanism and...¶

Given the data we already have on the mechanism and timeline of COVID infection, it is not unreasonable to predict that you can get reinfected with the same strain repeatedly. SARS-COV-2 slows down innate immune response and replicates quickly before adaptive immunity kicks in. https://t.co/D52v60Oyus This means that even with the memory cells generated by prior exposure (infection or vaccination), there is still that delay. The difference in outcome between immune and naive individuals comes into play only once that adaptive immune response kicks in. If you were recently exposed, you'll still have antibodies floating around as part of the humoral immune system. But some data suggests that antibody levels decline pretty quickly, hence the need for boosters. This also accounts for the difference in health outcomes between naive and immune populations. The virus can still replicate quickly before adaptive immune response. But once that response kicks in, a vaccinated person has plenty of immune memory to draw on to beat the infection. Bottom line: unless you still have high levels of antibodies from recent exposure, you can get infected. That could mean people get reinfected with an old strain if it's been a long time. When they do, it will probably be mild! But it can still bounce around in the population. This article is an easy to read review of adaptive immunity in SARS-COV-2, and cites some other good papers! https://t.co/qyGULRg0oL