Heterologous Booster Dose with CORBEVAX following Primary Vaccination with COVISHIELD Enhances Protection against SARS-CoV-2.

Despite effective vaccination programs, waning immunity in the vaccinated populations and the emergence of variants of concern posed a risk of breakthrough infections. A booster dose was demonstrated to provide substantially increased protection against symptomatic disease and hospitalization. We aimed to evaluate immune memory and the efficacy of reducing the rate of SARS-CoV-2 infection post heterologous booster with CORBEVAX after primary vaccination with two doses of COVISHIELD.

Clinical outcomes in individuals hospitalized with SARS-CoV-2 Delta variant (B.1.617.2) who had been vaccinated with Covishield (ChAdOx1) and Covaxin (BBV-152).

Background: Covishield (ChAdOx) and Covaxin (BBV-152) are the mainstream vaccines against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) used in India and a few other countries.

Objective: To assess the clinical outcomes of patients hospitalized with coronavirus disease 2019 (COVID-19) who had been vaccinated with either Covishield or Covaxin.

Methods: This prospective, single-centre, observational cohort study of 1160 patients hospitalized with COVID-19 was conducted between April and June 2021.