Challenges in Estimating the Effectiveness of COVID-19 Vaccination Using Observational Data.

ABSTRACT: The COVID-19 vaccines were developed and rigorously evaluated in randomized trials during 2020. However, important questions, such as the magnitude and duration of protection, their effectiveness against new virus variants, and the effectiveness of booster vaccination, could not be answered by randomized trials and have therefore been addressed in observational studies. Analyses of observational data can be biased because of confounding and because of inadequate design that does not consider the evolution of the pandemic over time and the rapid uptake of vaccination. Emulating a hypothetical "target trial" using observational data assembled during vaccine rollouts can help manage such potential sources of bias. This article describes 2 approaches to target trial emulation. In the sequentia

SUBMITTER: Hulme WJ 

PROVIDER: S-EPMC10152408 | biostudies-literature | 2023 May

REPOSITORIES: biostudies-literature