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Volume 29, Number 3—March 2023

Comparative Effectiveness of COVID-19 Vaccines in Preventing Infections and Disease Progression from SARS-CoV-2 Omicron BA.5 and BA.2, Portugal

Irina Kislaya1Comments to Author , Pedro Casaca1, Vítor Borges, Carlos Sousa, Bibiana I. Ferreira, Ana Fonte, Eugénia Fernandes, Carlos Matias Dias, Sílvia Duarte, José Pedro Almeida, Inês Grenho, Luís Coelho, Rita Ferreira, Patrícia Pita Ferreira, Cláudia Medeiros Borges, Joana Isidro, Miguel Pinto, Luís Menezes, Daniel Sobral, Alexandra Nunes, Daniela Santos, António Maia Gonçalves, Luís Vieira, João Paulo Gomes, Pedro Pinto Leite, Baltazar Nunes, Ausenda Machado2, and André Peralta-Santos2
Author affiliations: Instituto Nacional de Saúde Doutor Ricardo Jorge, Lisbon, Portugal (I. Kislaya, V. Borges, C. Matias Dias, S. Duarte, L. Coelho, R. Ferreira, J. Isidro, M. Pinto, D. Sobral, A. Nunes, D. Santos, L. Vieira, J.P. Gomes, B. Nunes, A. Machado); Comprehensive Health Research Centre, Lisbon (I. Kislaya, C. Matias Dias, B. Nunes, A. Machado, A. Peralta-Santos); Direção-Geral da Saúde, Lisbon (P. Casaca, E. Fernandes, P. Pita Ferreira, P. Pinto Leite, A. Peralta-Santos); Unilabs, Porto, Portugal (C. Sousa, J.P. Almeida, L. Menezes, A. Maia Gonçalves); Algarve Biomedical Center Research Institute, Faro, Portugal (B.I. Ferreira, I. Grenho); Administração Central do Sistema de Saúde, Lisbon (A. Fonte, C.M. Borges)

Main Article

Table 3

Adjusted odds ratios of hospitalization among COVID-19 case-patients, by SARS-CoV-2 variant, Portugal, 2022*

Vaccination status BA.5
aOR BA.5/BA.2 (95% CI)
No. (%) aOR (95% CI) No. (%) aOR (95% CI)
Not vaccinated 9/590 (1.53) Referent 14/631 (2.2) Referent
Complete primary vaccination 9/2,530 (0.36) 0.78 (0.29–2.09) 11/2,434 (0.45) 0.38 (0.16–0.89) 2.06 (0.56–7.55)
1st booster vaccination 34/9,186 (0.37) 0.23 (0.10–0.51) 29/12,331 (0.24) 0.07 (0.03–0.14) 3.36 (1.18–9.63)

*aOR, adjusted odds ratio; OR, odds ratio.

Main Article

1These first authors contributed equally to this article.

2These authors contributed equally to this article.

Page created: December 31, 2022
Page updated: February 19, 2023
Page reviewed: February 19, 2023
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