COVID-19 vaccines effectiveness against symptomatic disease and severe outcomes, 2021-2022: a test-negative case-control study.

ABSTRACT:

Objectives

This study evaluated the effectiveness of COVID-19 vaccines in preventing symptomatic and severe disease.

Study design

This was an observational test-negative case-control study.

Methods

Study participants were adults with at least one symptom included in the World Health Organization COVID-19 definition who sought health care in a public emergency department between 1 November 2021 and 2 March 2022 (corresponding with the fifth pandemic wave in Portugal dominated by the Omicron variant). This study used multivariable logistic regression models to estimate and compare the odds ratio of vaccination between test-positive cases and test-negative controls to calculate the absolute and relative vaccine effectiveness.

Results

The study included 1059 indivi

SUBMITTER: Brazete C 

PROVIDER: S-EPMC9943732 | biostudies-literature | 2023 May

REPOSITORIES: biostudies-literature