Este artigo é um Preprint
Preprints são relatos preliminares de pesquisa que não foram certificados pela revisão por pares. Eles não devem ser considerados para orientar a prática clínica ou comportamentos relacionados à saúde e não devem ser publicados na mídia como informação estabelecida.
Preprints publicados online permitem que os autores recebam feedback rápido, e toda a comunidade científica pode avaliar o trabalho independentemente e responder adequadamente. Estes comentários são publicados juntamente com os preprints para qualquer pessoa ler e servir como uma avaliação pós-publicação.
Effectiveness of COVID-19 vaccines against hospitalization and death in Canada: A multiprovincial test-negative design study
Preprint
em Inglês
| medRxiv
| ID: ppmedrxiv-22273825
ABSTRACT
BackgroundA major goal of COVID-19 vaccination is to prevent severe outcomes (hospitalizations and deaths). We estimated the effectiveness of mRNA and ChAdOx1 COVID-19 vaccines against severe outcomes in four Canadian provinces between December 2020 and September 2021. MethodsWe conducted this multiprovincial retrospective test-negative study among community-dwelling adults aged [≥]18 years in Ontario, Quebec, British Columbia, and Manitoba using linked provincial databases and a common study protocol. Multivariable logistic regression was used to estimate province-specific vaccine effectiveness against COVID-19 hospitalization and/or death. Estimates were pooled using random effects models. ResultsWe included 2,508,296 tested subjects, with 31,776 COVID-19 hospitalizations and 5,842 deaths. Vaccine effectiveness was 83% after a first dose, and 98% after a second dose, against both hospitalization and death (separately). Against severe outcomes (hospitalization or death), effectiveness was 87% (95%CI 71%-94%) [≥]84 days after a first dose of mRNA vaccine, increasing to 98% (95%CI 96%-99%) [≥]112 days after a second dose. Vaccine effectiveness against severe outcomes for ChAdOx1 was 88% (95%CI 75%-94%) [≥]56 days after a first dose, increasing to 97% (95%CI 91%-99%) [≥]56 days after a second dose. Lower one-dose effectiveness was observed for adults aged [≥]80 years and those with comorbidities, but effectiveness became comparable after a second dose. Two doses of vaccines provided very high protection for both homologous and heterologous schedules, and against Alpha, Gamma, and Delta variants. ConclusionsTwo doses of mRNA or ChAdOx1 vaccines provide excellent protection against severe outcomes of hospitalization and death.
cc_by_nc_nd
Texto completo:
Disponível
Coleções:
Preprints
Base de dados:
medRxiv
Tipo de estudo:
Experimental_studies
/
Estudo observacional
/
Rct
Idioma:
Inglês
Ano de publicação:
2022
Tipo de documento:
Preprint