Relative Effectiveness of COVID-19 Vaccination in Healthcare Workers:3-Dose Versus 2-Dose Vaccination
10.3346/jkms.2022.37.e267
- Author:
Sung Ran KIM
1
;
Hyeon Jeong KANG
;
Hye Rin JEONG
;
Su Yeon JANG
;
Jae Eun LEE
;
Da Eun KIM
;
Hae Ry LEE
;
Min Hee CHO
;
Ji Yun NOH
;
Hee Jin CHEONG
;
Woo Joo KIM
;
Joon Young SONG
Author Information
1. Infection Control Team, Korea University Guro Hospital, Seoul, Korea
- Publication Type:Brief Communication
- From:Journal of Korean Medical Science
2022;37(35):e267-
- CountryRepublic of Korea
- Language:English
-
Abstract:
The omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is known to have high infectivity and is more likely to evade vaccine immunity. However, booster vaccination is expected to strengthen cross-reactive immunity, thereby increasing the vaccine effectiveness (VE). This study aimed to evaluate the relative VE of the 3-dose (booster) vaccination compared with the 2-dose primary series vaccination in healthcare workers during omicron variant-dominant periods. During the omicron-dominant period from February 1, 2022 to February 28, 2022, a 1:1 matched case-control study was conducted.Healthcare workers with positive SARS-CoV-2 test results were classified as positive cases, whereas those with negative results served as controls. Compared with the 2-dose primary series vaccination, booster vaccination with mRNA vaccine showed moderate VE (53.1%).However, in multivariate analysis including the time elapsed after vaccination, the significant VE disappeared, reflecting the impact of recent vaccination rather than the third dose itself.
