Estimated Effectiveness of COVID-19 Vaccines Against Omicron or Delta Symptomatic Infection and Severe Outcomes.

ABSTRACT:

Importance

The incidence of SARS-CoV-2 infection, including among individuals who have received 2 doses of COVID-19 vaccine, increased substantially following the emergence of the Omicron variant in Ontario, Canada. Understanding the estimated effectiveness of 2 or 3 doses of COVID-19 vaccine against outcomes associated with Omicron and Delta infections may aid decision-making at the individual and population levels.

Objective

To estimate vaccine effectiveness (VE) against symptomatic infections due to the Omicron and Delta variants and severe outcomes (hospitalization or death) associated with these infections.

Design, setting, and participants

This test-negative case-control study used linked provincial databases for SARS-CoV-2 laboratory testing, reportable disease

SUBMITTER: Buchan SA 

PROVIDER: S-EPMC9500552 | biostudies-literature | 2022 Sep

REPOSITORIES: biostudies-literature