Influenza vaccine effectiveness against laboratory-confirmed influenza in hospitalised adults aged 60 years or older, Valencia Region, Spain, 2017/18 influenza season.
Euro Surveill
; 24(31)2019 Aug.
Article
em En
| MEDLINE
| ID: mdl-31387672
IntroductionInfluenza immunisation is recommended for elderly people each season. The influenza vaccine effectiveness (IVE) varies annually due to influenza viruses evolving and the vaccine composition.AimTo estimate, in inpatients ≥ 60 years old, the 2017/18 trivalent IVE, overall, by vaccine type and by strain. The impact of vaccination in any of the two previous seasons (2016/17 and 2015/16) on current (2017/18) IVE was also explored.MethodsThis was a multicentre prospective observational study within the Valencia Hospital Surveillance Network for the Study of Influenza and Respiratory Viruses Disease (VAHNSI, Spain). The test-negative design was applied taking laboratory-confirmed influenza as outcome and vaccination status as main exposure. Information about potential confounders was obtained from clinical registries and/or by interviewing patients; vaccine information was only ascertained by registries.ResultsOverall, 2017/18 IVE was 9.9% (95% CI: -15.5 to 29.6%), and specifically, 48.3% (95% CI: 13.5% to 69.1%), -29.9% (95% CI: -79.1% to 5.8%) and 25.7% (95% CI: -8.8% to 49.3%) against A(H1N1)pdm09, A(H3N2) and B/Yamagata lineage, respectively. For the adjuvanted and non-adjuvanted vaccines, overall IVE was 10.0% (95% CI: -24.4% to 34.9%) and 7.8% (95% CI: -23.1% to 31.0%) respectively. Prior vaccination significantly protected against influenza B/Yamagata lineage (IVE: 50.2%; 95% CI: 2.3% to 74.6%) in patients not vaccinated in the current season. For those repeatedly vaccinated against influenza A(H1N1)pdm09, IVE was 46.4% (95% CI: 6.8% to 69.2%).ConclusionOur data revealed low vaccine effectiveness against influenza in hospitalised patients ≥60 years old in 2017/18. Prior vaccination protected against influenza A(H1N1)pdm09 and B/Yamagata-lineage.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Vírus da Influenza B
/
Vacinas contra Influenza
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Influenza Humana
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Vírus da Influenza A Subtipo H1N1
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Vírus da Influenza A Subtipo H3N2
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Hospitalização
Tipo de estudo:
Observational_studies
Limite:
Aged
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Female
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Humans
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Male
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Middle aged
País/Região como assunto:
Europa
Idioma:
En
Revista:
Euro Surveill
Assunto da revista:
DOENCAS TRANSMISSIVEIS
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
Espanha