Effectiveness of Bivalent mRNA Booster Vaccine Against COVID-19 in Korea
- Author:
Jin Gu YOON
1
;
Jang Wook SOHN
;
Won Suk CHOI
;
Seong-Heon WIE
;
Jacob LEE
;
Jin-Soo LEE
;
Hye Won JEONG
;
Joong Sik EOM
;
Hye SEONG
;
Eliel NHAM
;
Yu Jung CHOI
;
Ji Yun NOH
;
Joon Young SONG
;
Hee Jin CHEONG
;
Woo Joo KIM
Author Information
- Publication Type:Original Article
- From:Journal of Korean Medical Science 2024;39(3):e15-
- CountryRepublic of Korea
- Language:EN
-
Abstract:
Background:Bivalent booster mRNA vaccines containing the omicron-variant strains have been introduced worldwide in the autumn of 2022. Nevertheless, the omicron subvariants evoked another large coronavirus disease 2019 (COVID-19) pandemic wave in late 2022 and early 2023.
Methods:A retrospective, test-negative, case-control study was conducted to estimate the vaccine effectiveness (VE) of bivalent COVID-19 vaccines in 8 university hospitals between January and February 2023. The case and control groups were divided based on nasopharyngeal COVID-19 real-time polymerase chain reaction results and matched based on age, sex, hospital, and date (week) of the test performed. The VE of the BA.1- or BA.4/BA.5-based mRNA vaccines were estimated. VE was calculated using the 1−adjusted odds ratio from multivariable logistic regression.
Results:In total, 949 patients and 947 controls were enrolled in this study. VE for the BA.4/ BA.5-based bivalent mRNA vaccine was 43% (95% confidence interval [CI], 17, 61%). In subgroup analysis based on age and underlying medical conditions, BA.4/BA.5-based bivalent mRNA vaccine was effective against old adults aged ≥ 65-years (VE, 55%; 95% CI, 23, 73%) and individuals with comorbidities (VE, 54%; 95% CI, 23, 73%). In comparison, the BA.1-based bivalent mRNA vaccine did not demonstrate statistically significant effectiveness (VE, 25%; 95% CI, −8, 49%).
Conclusion:The BA.4/BA.5-based bivalent mRNA booster vaccine provided significant protection against COVID-19 in the Korean adults, especially in the older adults aged ≥ 65 years and in individuals with underlying medical conditions.
