Comparing the effectiveness of bivalent and monovalent COVID-19 vaccines against COVID-19 infection during the winter season of 2022-2023: A real-world retrospective observational matched cohort study in the Republic of Korea

• DOI: 10.1016/j.ijid.2023.08.010
• Publication Date: 2023-08-11T01:30:27Z
• Authors: Chungman Chae; Ryu Kyung Kim; Eun Jung Jang; Ji Ae Shim; Eunkyung Park; Kil Hun Lee; Sye Lim Hong; Asma Binte Aziz; Birkneh Tilahun T...; Florian Marks; Sangwoo Tak; Sangwon Lee; Donghyok Kwon
• Keywords: Bivalent (engine)

To compare the effectiveness of bivalent and monovalent COVID-19 vaccines throughout 2022-2023 winter season based on real-world data.This retrospective observational matched cohort study used national vaccination program a surveillance dataset from Republic Korea, included adults aged >18 years who received or between October 11, 2022, December 17, 2022. Cox proportional hazard models were to estimate ratio for infection groups.We 29,245 individuals in vaccine groups, respectively. The recipients showed 12.2% (95% confidence interval [CI] 6.5-17.7%) additional protection against compared with recipients. provided by was significantly higher among residents long-term care facilities (39.4%, 95% CI 21.6-53.1%). Maximum observed 3 4 months after completing (17.6%, 6.6-27.3%).Bivalent better than during season. Our results highlight that immunization programs comprising recent variants can be an effective measure prepare seasonal circulation.