Real-world effectiveness of the CoronaVac vaccine in a retrospective population-based cohort in four Colombian cities (2021-2022).

Objectives: The National Vaccination Plan against SARS-CoV-2/COVID-19 was launched by the Ministry of Health and Social Protection on 14 February 2021. The main objective of this study was to evaluate the effectiveness of the CoronaVac in preventing the three clinical outcomes of infection, hospitalisation, or death, in a real-world scenario.

Design: This was a population-based retrospective dynamic cohort study using a multivariate Cox model to calculate hazard ratios to estimate vaccine effectiveness from 17 February 2021 to 30 June 2022.