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

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; Regional COVID-19 VE in Adults Study Working Group

doi:10.1016/j.lana.2023.100474

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

Lancet Reg Health Am. 2023 Apr:20:100474. doi: 10.1016/j.lana.2023.100474. Epub 2023 Mar 29.

Authors

Rebecca Kahn¹, Cara B Janusz², Marcia C Castro³, Aline da Rocha Matos⁴, Carla Domingues⁵, Jamie Ponmattam³, Gloria Rey-Benito⁶, Cristiana M Toscano⁷, Lucia Helena de Oliveira⁶; Regional COVID-19 VE in Adults Study Working Group

Collaborators

Regional COVID-19 VE in Adults Study Working Group:
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

Affiliations

¹ Harvard TH Chan School of Public Health, 677 Huntington Ave Suite 506, Boston, MA, 02115, USA.
² University of Michigan, 2800 Plymouth Road, Ann Arbor, MI, 48109, USA.
³ Harvard TH Chan School of Public Health, 665 Huntington Avenue, Building 1, Room 1102A, Boston, MA, 02115, USA.
⁴ Laboratory of Respiratory Viruses, Exanthematics, Enteroviruses and Viral Emergencies, Oswaldo Cruz Institute, Fiocruz, Rio de Janeiro, Brazil.
⁵ SMDB conjunto 12b lote 3 Casa B. Brasília DF., Brazil.
⁶ Immunization Unit, Pan American Health Organization, Washington, USA.
⁷ Federal University of Goiás (UFG), Institute of Tropical Pathology and Public Health. Rua 235 s/n. Setor Leste Universitario, Goiânia/GO, Brazil.

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.

Keywords: Argentina; Brazil; COVID-19 vaccination; Case–control; Chile; Colombia; Test-negative; Vaccine effectiveness.