Effectiveness of heterologous COVID-19 vaccine booster dosing in Brazilian healthcare workers, 2021.

ABSTRACT:

Objectives

Little is currently known about vaccine effectiveness (VE) for either two doses of Oxford-AstraZeneca (ChAdOx1) viral vector vaccine or CoronaVac inactivated viral vaccine followed by a third dose of mRNA vaccine (Pfizer/BioNTech) among healthcare workers (HCWs).

Methods

We conducted a retrospective cohort study among HCWs (aged ≥18 years) working in a private healthcare system in Brazil from January to December 2021. VE was defined as 1-IRR (incidence rate ratio), with IRR determined using Poisson models with the occurrence of laboratory-confirmed COVID-19 infection as the outcome, adjusting for age, sex, and job type. We compared those receiving viral vector or inactivated viral primary series (two doses) to those who received an mRNA booster.

Results

A t

SUBMITTER: Marra AR 

PROVIDER: S-EPMC9213833 | biostudies-literature | 2022 May

REPOSITORIES: biostudies-literature