Protection Against the Omicron Variant Offered by Previous Severe Acute Respiratory Syndrome Coronavirus 2 Infection: A Retrospective Cohort Study.
Clin Infect Dis
; 76(3): e142-e147, 2023 02 08.
Article
em En
| MEDLINE
| ID: mdl-35867678
ABSTRACT
BACKGROUND:
Previous infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) provides strong protection against future infection. There is limited evidence on whether such protection extends to the Omicron variant.METHODS:
This retrospective cohort study included 635 341 patients tested for SARS-CoV-2 via polymerase chain reaction from 9 March 2020 to 1 March 2022. Patients were analyzed according to the wave in which they were initially infected. The primary outcome was reinfection during the Omicron period (20 December 2021-1 March 2022). We used a multivariable model to assess the effects of prior infection and vaccination on hospitalization.RESULTS:
Among the patients tested during the Omicron wave, 30.6% tested positive. Protection of prior infection against reinfection with Omicron ranged from 18.0% (95% confidence interval [CI], 13.0-22.7) for patients infected in wave 1 to 69.2% (95% CI, 63.4-74.1) for those infected in the Delta wave. In adjusted models, previous infection reduced hospitalization by 28.5% (95% CI, 19.1-36.7), whereas full vaccination plus a booster reduced it by 59.2% (95% CI, 54.8-63.1).CONCLUSIONS:
Previous infection offered less protection against Omicron than was observed in past waves. Immunity against future waves will likely depend on the degree of similarity between variants.Palavras-chave
Texto completo:
1
Bases de dados:
MEDLINE
Assunto principal:
COVID-19
Tipo de estudo:
Etiology_studies
/
Observational_studies
Limite:
Humans
Idioma:
En
Revista:
Clin Infect Dis
Assunto da revista:
DOENCAS TRANSMISSIVEIS
Ano de publicação:
2023
Tipo de documento:
Article
País de afiliação:
Estados Unidos