COVID reinfections are unusual — but could still help the virus to spread
Large study of UK health-care workers suggests that most people are immune for months after catching COVID-19 for the first time.
Most people who catch and recover from COVID-19 are likely to be immune for several months afterwards, a study of more than 20,000 health-care workers in the United Kingdom has found…The study — called SARS-CoV-2 Immunity and Reinfection Evaluation (SIREN) — concluded that immune responses from past infection reduce the risk of catching the virus again by 83% for at least 5 months.
The data suggest that natural immunity might be as effective as vaccination, she added, at least over the five-month period the study has covered so far.
The data suggest that repeat infections are rare — they occurred in fewer than 1% of about 6,600 participants who had already been ill with COVID-19. But the researchers also found that people who become reinfected can carry high levels of the virus in their nose and throat, even when they do not show symptoms. Such viral loads have been associated with a high risk of transmitting the virus to others…