Effectiveness of mRNA COVID-19 Monovalent and Bivalent Vaccine Booster Doses Against Omicron Severe Outcomes Among Adults Aged ≥50 Years in Ontario, Canada: A Canadian Immunization Research Network Study.

Grewal, Ramandip; Buchan, Sarah A; Nguyen, Lena; Nasreen, Sharifa; Austin, Peter C; Brown, Kevin A; Gubbay, Jonathan; Lee, Nelson et al. · J Infect Dis · 2024

retrospective_cohort · Level III

Where this comes from

Abstract

We estimated the effectiveness of booster doses of monovalent and bivalent mRNA COVID-19 vaccines against Omicron-associated severe outcomes among adults aged ≥50 years in Ontario, Canada. Monovalent and bivalent mRNA COVID-19 booster doses provided similar strong initial protection against severe outcomes. Uncertainty remains around waning of protection from these vaccines.

Medical subject headings