CDC study: COVID-19 antibodies decline over time

Antibodies for SARS-CoV-2 were undetectable in 28% of front-line health care workers who tested positive 60 days earlier, according to a study of 156 employees in a multistate hospital network. Almost all study participants—94%—showed a decline in antibody levels. Participants with higher initial antibody responses were more likely to have antibodies detected at the follow-up test than were those who had a lower initial antibody response. The study has implications for how negative results of serologic tests are interpreted. (MMWR article, 11/27/20)