Vaccine effectiveness of ChAdOx1 nCoV-19 against COVID-19 in a socially vulnerable community in Rio de Janeiro, Brazil: a test-negative design study

• DOI: 10.1016/j.cmi.2022.01.032
• Publication Date: 2022-02-09T16:51:51Z
• Authors: Otavio T. Ranzani; Amanda A.B. Silva; Igor T. Peres; Bianca B.P. Antunes; Thiago W. Gonzaga...; Daniel R. Soranz; José Cerbino-Neto; Silvio Hamacher; Fernando A. Bozza
• Keywords: Vaccine efficacy

To estimate vaccine effectiveness after the first and second dose of ChAdOx1 nCoV-19 against symptomatic COVID-19 infection in a socially vulnerable community Brazil when Gamma Delta were predominant variants circulating.We conducted test-negative study Complexo da Maré, largest group slums (n = 16) Rio de Janeiro, Brazil, from January 17, 2021 to November 27, 2021. We selected RT-qPCR positive negative tests broad testing program. The primary outcome was (positive test with at least one symptom) secondary (any test). Vaccine estimated as 1 - OR, which obtained adjusted logistic regression models.We included 10 077 (6,394, 64% 3,683, 36% asymptomatic individuals). mean age 40 (SD: 14) years, median time between vaccination among vaccinated 41 (25-75 percentile: 21-62) days for 36 17-59) dose. Adjusted 31.6% (95% CI, 12.0-46.8) 21 65.1% 40.9-79.4) 14 31.0% 12.7-45.5) 59.0% 33.1-74.8) dose.ChAdOx1 effective reducing circulating.