TY - JOUR AU - Kislaya, Irina AU - Casaca, Pedro AU - Borges, Vítor AU - Sousa, Carlos AU - Ferreira, Bibiana AU - Fonte, Ana AU - Fernandes, Eugénia AU - Dias, Carlos Matias AU - Duarte, Sílvia AU - Almeida, José Pedro AU - Grenho, Inês AU - Coelho, Luís AU - Ferreira, Rita AU - Ferreira, Patrícia Pita AU - Borges, Cláudia Medeiros AU - Isidro, Joana AU - Pinto, Miguel AU - Menezes, Luís AU - Sobral, Daniel AU - Nunes, Alexandra AU - Santos, Daniela AU - Gonçalves, António Maia AU - Vieira, Luís AU - Gomes, João Paulo AU - Leite, Pedro Pinto AU - Nunes, Baltazar AU - Machado, Ausenda AU - Peralta-Santos, André T1 - Comparative Effectiveness of COVID-19 Vaccines in Preventing Infections and Disease Progression from SARS-CoV-2 Omicron BA.5 and BA.2, Portugal T2 - Emerging Infectious Disease journal PY - 2023 VL - 29 IS - 3 SP - 569 SN - 1080-6059 AB - We estimated comparative primary and booster vaccine effectiveness (VE) of SARS-CoV-2 Omicron BA.5 and BA.2 lineages against infection and disease progression. During April–June 2022, we implemented a case–case and cohort study and classified lineages using whole-genome sequencing or spike gene target failure. For the case–case study, we estimated the adjusted odds ratios (aORs) of vaccination using a logistic regression. For the cohort study, we estimated VE against disease progression using a penalized logistic regression. We observed no reduced VE for primary (aOR 1.07 [95% CI 0.93–1.23]) or booster (aOR 0.96 [95% CI 0.84–1.09]) vaccination against BA.5 infection. Among BA.5 case-patients, booster VE against progression to hospitalization was lower than that among BA.2 case-patients (VE 77% [95% CI 49%–90%] vs. VE 93% [95% CI 86%–97%]). Although booster vaccination is less effective against BA.5 than against BA.2, it offers substantial protection against progression from BA.5 infection to severe disease. KW - COVID-19 KW - coronavirus disease KW - SARS-CoV-2 KW - severe acute respiratory syndrome coronavirus 2 KW - viruses KW - respiratory infections KW - zoonoses KW - vaccine-preventable diseases KW - Omicron KW - BA.2 KW - BA.5 KW - postinfection vaccine effectiveness KW - hospitalization KW - death KW - Portugal DO - 10.3201/eid2903.221367 UR - https://wwwnc.cdc.gov/eid/article/29/3/22-1367_article ER - End of Reference