Effect of Repeated Vaccination With the Same Vaccine Component Against 2009 Pandemic Influenza A(H1N1) Virus.
J Infect Dis
; 215(6): 847-855, 2017 03 15.
Article
en En
| MEDLINE
| ID: mdl-28453845
ABSTRACT
Background:
The 2009 pandemic influenza A(H1N1) (A[H1N1]pdm09) vaccine component has remained unchanged from 2009. We estimate the effectiveness of current and prior inactivated influenza A(H1N1)pdm09 vaccination from influenza seasons 2010-2011 to 2015-2016.Methods:
Patients attended with influenza-like illness were tested for influenza. Four periods with continued A(H1N1)pdm09 circulation were included in a test-negative design.Results:
We enrolled 1278 cases and 2343 controls. As compared to individuals never vaccinated against influenza A(H1N1)pdm09, the highest effectiveness (66%; 95% confidence interval, 49%-78%) was observed in those vaccinated in the current season who had received 1-2 prior doses. The effectiveness was not statistically lower in individuals vaccinated in the current season only (52%) or in those without current vaccination and >2 prior doses (47%). However, the protection was lower in individuals vaccinated in the current season after >2 prior doses (38%; P = .009) or those currently unvaccinated with 1-2 prior doses (10%; P < .001). Current-season vaccination improved the effect in individuals with 1-2 prior doses and did not modify significantly the risk of influenza in individuals with >2 prior doses.Conclusion:
Current vaccination or several prior doses were needed for high protection. Despite the decreasing effect of repeated vaccination, current-season vaccination was not inferior to no current-season vaccination.Palabras clave
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Vacunas contra la Influenza
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Gripe Humana
Tipo de estudio:
Observational_studies
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Risk_factors_studies
Límite:
Adolescent
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Adult
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Aged
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Aged80
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Child
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Child, preschool
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Female
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Humans
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Male
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Middle aged
País como asunto:
Europa
Idioma:
En
Año:
2017
Tipo del documento:
Article