A test-negative case–control analysis using data from a diverse population in California, USA, demonstrates that vaccine efficacy of a three-dose regimen of the mRNA-1273 COVID-19 vaccine is reduced against infection with the Omicron SARS-CoV-2 variant in comparison to Delta, but that efficacy against hospitalization remained high for both variants.
- Hung Fu Tseng
- Bradley K. Ackerson
- Lei Qian
