Abstract
OBJECTIVES: To explore whether monoclonal antibodies (MAb) administered to high-risk patients with COVID-19 during the first week of illness prevent postacute sequelae of SARS-CoV-2 infection. DESIGN: Retrospective cohort study. SETTING: USA. PARTICIPANTS: A sample of 3809 individuals who received MAbs and a matched one-to-one comparison group from a set of 327 079 eligible patients who did not receive MAb treatment were selected from a deidentified administrative data set from commercial and Medicare Advantage health plan enrollees in the USA, including claims and outpatient laboratory data. RESULTS: Individuals who received MAb were 28% less likely to be hospitalised (HR=0.72, 95% CI 0.58 to 0.89) and 41% less likely to be admitted to the intensive care unit (HR=0.59, 95% CI 0.38 to 0.89) 30 days from SARS-CoV-2 diagnosis compared with individuals who did not receive MAb. A higher proportion of individuals given MAb therapy received care for clinical sequelae in the postacute phase (p=0.018). CONCLUSIONS: While MAb therapy was associated with benefits in the acute period, the benefit of therapy did not extend into the postacute period and did not reduce risk for clinical sequelae.