A Hong Kong man who recovered from COVID-19 more than four months ago has reportedly been reinfected with SARS-CoV-2, the virus that causes COVID-19. This time he didn’t have any symptoms.
This is not necessarily unexpected, because very few natural infections generate an immune response that completely prevents reinfection. Instead, what generally happens after an infection is that the body’s immune response gradually declines over months after the infection is cleared.
Specialised immune cells in the body are tasked with remembering each particular infection, so if you get infected again your body quickly starts producing the relevant antibodies and other