Quantifying the direct and indirect components of COVID-19 vaccine effectiveness during the Delta variant era.

ABSTRACT: The efficacy of COVID-19 vaccines against the Delta variant has been observed to be high, both against severe disease and infection. The full population level vaccine effectiveness, however, also contains the indirect effects of vaccination, which require analysis of transmission dynamics to uncover. Finland was close to naïve to SARS-CoV-2 infections before the Delta dominant era, and non-pharmaceutical interventions (NPIs) were at an internationally low level. We utilize Finnish register data and a mathematical model for transmission and COVID-19 disease burden to construct a completely unvaccinated control population and estimate the different components of the vaccine effectiveness. The estimated direct effectiveness was 72% against COVID-19 cases and 87-96% against severe disease outc

SUBMITTER: Suomenrinne-Nordvik A 

PROVIDER: S-EPMC12001148 | biostudies-literature | 2025 Mar

REPOSITORIES: biostudies-literature