People who had COVID-19 had an 84% lower risk of becoming reinfected and a 93% lower risk of symptomatic infection during 7 months of follow-up, according to findings from a large, multicenter study published late last week in The Lancet.The prospective cohort SARS-CoV-2 Immunity and Reinfection Evaluation (SIREN) study, by Public Health England Colindale researchers, involved 25,661 workers at public hospitals throughout England who were tested for SARS-CoV-2 every 2 to 4 weeks and antibodies at enrollment and every 4 weeks.
Volunteers also completed questionnaires on symptoms and exposures every 2 weeks.Of the 25,661 participants, 32.3% were assigned to the baseline positive (possibly or probably previously infected) group, and 67.7% were