Safety of BA.4-5 or BA.1 bivalent mRNA booster vaccines: nationwide cohort study.

ABSTRACT:

Objective

To examine the association between the omicron adapted bivalent mRNA covid-19 booster vaccines received as a fourth dose and risk of adverse events.

Design

Nationwide cohort study.

Setting

Denmark.

Participants

2 225 567 adults aged ≥50 years who received three covid-19 vaccine doses during the study period, 1 January 2021 to 10 December 2022.

Main outcome measures

The main outcome measure was rates of hospital visits for 27 different adverse events in a 28 day main risk period after vaccination with a bivalent omicron adapted mRNA booster vaccine as a fourth dose compared with reference period rates from day 29 after the third or fourth vaccine dose and onward.

Results

1 740 417 adults (mean age 67.8 years, standard deviation 10.7 years

SUBMITTER: Andersson NW 

PROVIDER: S-EPMC10364193 | biostudies-literature | 2023 Jul

REPOSITORIES: biostudies-literature