Duration of protection of ancestral-strain monovalent vaccines and effectiveness of bivalent BA.1 boosters against COVID-19 hospitalisation in England: a test-negative case-control study
Description
BACKGROUND: Bivalent BA.1 booster vaccines were offered to adults aged 50 years or older and clinically vulnerable people as part of the 2022 autumn COVID-19 booster vaccination programme in England. Previously, all adults in England had been offered
