The effectiveness of COVID-19 vaccines in Latin America, 2021: a multicenter regional case–control study
Rebecca Kahn, Cara Bess Janusz, Márcia C. Castro, Aline da Rocha Matos, Carla Magda Allan Santos Domingues, Jamie Ponmattam, Gloria Rey-Benito, Cristiana M. Toscano, Lúcia Helena de Oliveira, Analía Rearte, Ignacio Leandro Uriarte, Elsa Baumester, María Elena Borda, Miguel Diaz Cordoba, Juan Facundo Petrina, Ezequiel Consiglio, Carla Vizzotti, Tatiana Guimarães de Noronha, Maria Paula Gomes Mourão, Jeová Keny Baima Colares, Sônia Mara Raboni, Tázio Vanni, Lely Guzman, Adriana Regina Farias Pontes Lucena, Marı́a Elena Santolaya, Cinthya Urquidi, Claudia P. Cortés, Pedro Pablo Usedo Lopez, Rosana Benítez, Veronica Menares Latorre, Andrea Moller Roth, Iván Brstilo Cerda, Solange Santillana, Zohra Abaakouk, Ángel Paternina Caicedo, Nelson Alvis‐Guzmán, J.C. Fernandez-Mercado, Fernando de la Hoz, David Santiago Quevedo, Diana Sofía Rios, Diane Moyano Romero
Abstract
Background: As of September 2022, nearly 1.3 billion doses of COVID-19 vaccine products have been administered in Latin America and the Caribbean, where 27% of global COVID-19 deaths have occurred. This study aimed to estimate the effectiveness of COVID-19 vaccines against lab-confirmed COVID-19 related hospitalizations and deaths among adults in Argentina, Brazil, Chile, and Colombia. Methods: Using a test-negative case control design, we evaluated the effectiveness of a primary vaccination series considering six COVID-19 vaccine products (Sputnik V, mRNA-1273, CoronaVac, ChAdOx1, BNT162b2, Ad26.COV2.S) against lab-confirmed COVID-19 hospitalizations and deaths among 83,708 hospitalized adults from February-December, 2021. Data from hospitalization records, COVID surveillance, and vaccination registries were used. Vaccine effectiveness was estimated using logistic regression ((1-OR) x 100). Findings: The average age of participants was 56.7 (SD = 17.5), and 45,894 (54.8%) were male. Adjusted VE (aVE) estimates for full vaccination against hospitalization were 82% for mRNA-1273 (95% confidence interval (CI) = -30 to 98%), 76% (71%-81%) for BNT162b2, 65% (61-68%) for ChAdOx1, 57% (10-79%) for Sputnik V, 53% (50-56%) for CoronaVac, and 46% (23-62%) for Ad26.COV2.S. Estimates, particularly for CoronaVac, varied by variant. Decreasing aVE was estimated as age increased, particularly for CoronaVac and ChAdOx1. aVE estimates against death were generally higher, with 100% (CI not estimated) for mRNA-1273, 82% (69-90%) for BNT162b2, 73% (69-77%) for ChAdOx1, 65% (60-67%) for CoronaVac, 38% (-75 to 78%) for Sputnik V, 6% (-58 to 44%) for Ad26.COV2.S. Interpretation: Primary series vaccination with available COVID-19 vaccine products was effective against COVID-19 hospitalization and mortality. Effectiveness varied by product and declined with increasing age. Funding: This study was funded by the Pan-American Health Organization (PAHO, World Health Organization (WHO)). PAHO convened and led the study implementation.