Effectiveness of Influenza Vaccination During Pregnancy Against Laboratory-Confirmed Seasonal Influenza Among Infants Under 6 Months of Age in Ontario, Canada.
J Infect Dis
; 230(1): e80-e92, 2024 Jul 25.
Article
em En
| MEDLINE
| ID: mdl-39052720
ABSTRACT
BACKGROUND:
Randomized trials conducted in low- and middle-income settings demonstrated efficacy of influenza vaccination during pregnancy against influenza infection among infants <6 months of age. However, vaccine effectiveness (VE) estimates from settings with different population characteristics and influenza seasonality remain limited.METHODS:
We conducted a test-negative study in Ontario, Canada. All influenza virus tests among infants <6 months from 2010 to 2019 were identified and linked with health databases to ascertain information on maternal-infant dyads. VE was estimated from the odds ratio for influenza vaccination during pregnancy among cases versus controls, computed using logistic regression with adjustment for potential confounders.RESULTS:
Among 23 806 infants tested for influenza, 1783 (7.5%) were positive and 1708 (7.2%) were born to mothers vaccinated against influenza during pregnancy. VE against laboratory-confirmed infant influenza infection was 64% (95% confidence interval [CI], 50%-74%). VE was similar by trimester of vaccination (first/second, 66% [95% CI, 40%-80%]; third, 63% [95% CI, 46%-74%]), infant age at testing (0 to <2 months, 63% [95% CI, 46%-75%]; 2 to <6 months, 64% [95% CI, 36%-79%]), and gestational age at birth (≥37 weeks, 64% [95% CI, 50%-75%]; < 37 weeks, 61% [95% CI, 4%-86%]). VE against influenza hospitalization was 67% (95% CI, 50%-78%).CONCLUSIONS:
Influenza vaccination during pregnancy offers effective protection to infants <6 months, for whom vaccines are not currently available.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Vacinas contra Influenza
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Vacinação
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Influenza Humana
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Eficácia de Vacinas
Limite:
Adult
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Female
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Humans
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Infant
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Male
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Newborn
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Pregnancy
País/Região como assunto:
America do norte
Idioma:
En
Revista:
J Infect Dis
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
Canadá
País de publicação:
Estados Unidos