However, up until now there have not been any large-scale studies of how much protection from re-infection people get after COVID-19. The health care workers were tested for antibodies to the virus that causes COVID-19 as a way of detecting who had been infected before. The hospital tested staff regularly for COVID-19, both when they became unwell with symptoms and also as part of regular testing of well staff. Staff with antibodies were also less likely to test positive for COVID-19 without symptoms, 76 staff without antibodies tested positive compared to just 3 with antibodies. Additionally, the opposite also proved true – health care workers who did not have antibodies against COVID-19 were more likely to develop the infection.
