Effectiveness of the ChAdOx1 nCoV-19 Coronavirus Vaccine (Covishield^TM) in Preventing SARS-CoV2 Infection, Chennai, Tamil Nadu, India, 2021.

ABSTRACT: We estimated the effectiveness of two doses of the ChAdOx1 nCoV-19 (Covishield) vaccine against any COVID-19 infection among individuals ≥45 years in Chennai, Tamil Nadu, India. A community-based cohort study was conducted from May to September 2021 in a selected geographic area in Chennai. The estimated sample size was 10,232. We enrolled 69,435 individuals, of which 21,793 were above 45 years. Two-dose coverage of Covishield in the 18+ and 45+ age group was 18% and 31%, respectively. Genomic analysis of 74 out of the 90 aliquots collected from the 303 COVID-19-positive individuals in the 45+ age group showed delta variants and their sub-lineages. The vaccine's effectiveness against COVID-19 disease in the ≥45 age group was 61.3% (95% CI: 43.6-73.4) at least 2 weeks after receiving the se

SUBMITTER: Murali S 

PROVIDER: S-EPMC9228854 | biostudies-literature | 2022 Jun

REPOSITORIES: biostudies-literature