Short term, relative effectiveness of four doses versus three doses of BNT162b2 vaccine in people aged 60 years and older in Israel: retrospective, test negative, case-control study.

ABSTRACT:

Objective

To examine the relative effectiveness of a fourth dose of the Pfizer-BioNTech mRNA (BNT162b2) vaccine compared with three vaccine doses over the span of 10 weeks.

Design

Retrospective, test negative, case-control study, with a matched analysis and an unmatched multiple tests analysis.

Setting

Nationally centralised database of Maccabi Healthcare Services, an Israeli national health fund for 2.5 million people; from 10 January 2022 (seven days after the fourth dose was first given to eligible individuals) to 13 March 2022, an omicron dominant period in Israel.

Participants

97 499 Maccabi Healthcare Services members aged 60 years and older, who were eligible to receive a fourth vaccine dose and obtained at least one polymerase chain reaction (PCR) test

SUBMITTER: Gazit S 

PROVIDER: S-EPMC9127435 | biostudies-literature | 2022 May

REPOSITORIES: biostudies-literature