5,69,519 eligible participants were identified between September 27, 2022, and January 25, 2023. Of those, 1,34,215 (24 per cent) participants received a bivalent mRNA booster vaccination during the study period. Hospitalisation due to COVID-19 occurred in 32 participants who received a bivalent mRNA booster vaccination and 541 who did not receive a bivalent booster vaccination. Analysis showed this to mean a 72 per cent reduction in hospitalisation risk in those receiving the bivalent booster.
