Antibody Status and Incidence of SARS-CoV-2 Infection in Health Care Workers

Study (12,541 healthcare workers at a UK Trust) found that those with antibodies had a significantly lower risk of a positive COVID PCR test vs those without antibodies over 6 months of follow up (1.09 vs 0.13 per 10,000 days at risk, RR 0.11, 95%CI 0.03-0.44).

New England Journal of Medicine