Influenza vaccine failure in the tropics: a retrospective cohort study of waning effectiveness.
Epidemiol Infect
; 148: e299, 2020 12 02.
Article
em En
| MEDLINE
| ID: mdl-33261680
ABSTRACT
Influenza vaccine effectiveness (VE) wanes over the course of a temperate climate winter season but little data are available from tropical countries with year-round influenza virus activity. In Singapore, a retrospective cohort study of adults vaccinated from 2013 to 2017 was conducted. Influenza vaccine failure was defined as hospital admission with polymerase chain reaction-confirmed influenza infection 2-49 weeks after vaccination. Relative VE was calculated by splitting the follow-up period into 8-week episodes (Lexis expansion) and the odds of influenza infection in the first 8-week period after vaccination (weeks 2-9) compared with subsequent 8-week periods using multivariable logistic regression adjusting for patient factors and influenza virus activity. Records of 19 298 influenza vaccinations were analysed with 617 (3.2%) influenza infections. Relative VE was stable for the first 26 weeks post-vaccination, but then declined for all three influenza types/subtypes to 69% at weeks 42-49 (95% confidence interval (CI) 52-92%, P = 0.011). VE declined fastest in older adults, in individuals with chronic pulmonary disease and in those who had been previously vaccinated within the last 2 years. Vaccine failure was significantly associated with a change in recommended vaccine strains between vaccination and observation period (adjusted odds ratio 1.26, 95% CI 1.06-1.50, P = 0.010).
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Vacinas contra Influenza
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Influenza Humana
Tipo de estudo:
Etiology_studies
/
Observational_studies
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Risk_factors_studies
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Screening_studies
Limite:
Humans
Idioma:
En
Revista:
Epidemiol Infect
Assunto da revista:
DOENCAS TRANSMISSIVEIS
/
EPIDEMIOLOGIA
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Singapura