The Lancet Regional Health. Americas (Apr 2023)

The effectiveness of COVID-19 vaccines in Latin America, 2021: a multicenter regional case–control studyResearch in context

  • Rebecca Kahn,
  • Cara B. Janusz,
  • Marcia C. Castro,
  • Aline da Rocha Matos,
  • Carla Domingues,
  • Jamie Ponmattam,
  • Gloria Rey-Benito,
  • Cristiana M. Toscano,
  • Lucia Helena de Oliveira,
  • Analia Rearte,
  • Ignacio Leandro Uriarte,
  • Elsa Baumester,
  • Maria Elena Borda,
  • Miguel Diaz Cordoba,
  • Juan Facundo Petrina,
  • Ezequiel Consiglio,
  • Carla Vizzotti,
  • Tatiana Guimarães de Noronha,
  • Maria Paula Gomes Mourão,
  • Jeova Keny Baima Colares,
  • Sonia Mara Raboni,
  • Tazio Vanni,
  • Lely Guzman,
  • Adriana Regina Farias Pontes Lucena,
  • Maria Elena Santolaya,
  • Cinthya Urquidi,
  • Claudia P. Cortes,
  • Pedro Pablo Usedo Lopez,
  • Rosana Benitez,
  • Veronica Menares Latorre,
  • Andrea Moller Roth,
  • Iván Brstilo Cerda,
  • Solange Santillana,
  • Zohra Abaakouk,
  • Angel Paternina Caicedo,
  • Nelson Alvis Guzman,
  • Juan Carlos Fernandez Mercado,
  • Fernando de la Hoz Restrepo,
  • David Santiago Quevedo,
  • Sofia Rios Oliveros,
  • Diane Moyano Romero

Journal volume & issue
Vol. 20
p. 100474

Abstract

Read online

Summary: 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.

Keywords