Moderate influenza vaccine effectiveness against A(H1N1)pdm09 virus, and low effectiveness against A(H3N2) subtype, 2018/19 season in Italy.
Expert Rev Vaccines
; 18(11): 1201-1209, 2019 11.
Article
en En
| MEDLINE
| ID: mdl-31674847
ABSTRACT
Background:
Influenza vaccines are updated every year to match the vaccine strains with currently circulating viruses; consequently influenza vaccine effectiveness (IVE) has to be assessed annually.Research design andmethods:
A test-negative case-control study was conducted within the context of the Italian sentinel influenza surveillance network to estimate IVE by age group, virus subtype, and vaccine brand in medically attended laboratory-confirmed influenza.Results:
In Italy, the 2018/19 influenza season was characterized by the co-circulation of influenza A(H1N1)pdm09 and A(H3N2) viruses. The adjusted IVE estimate in preventing influenza was moderate (44.8%, 95% CI 18.8 to 62.5) against A(H1N1)pdm09, whereas there was no evidence of effectiveness (1.8%, 95% CI -37.8 to 30.1) in persons affected by A(H3N2). IVE against A(H1N1)pdm09 decreased with age ranging from 65.7% to 13.1% among children/adolescents and elderly, respectively; moreover results suggest that Vaxigrip Tetra® was more effective against A(H1N1)pdm09 compared to Fluarix Tetra® [62.5% (95% CI 34.3 to 78.6) vs 24.5% (95% CI -40.6 to 59.6)]. Low effectiveness (35.2%, 95% CI -50.8 to 72.1) against A(H3N2) was detected only in the elderly immunized with Fluad®.Conclusions:
Findings suggest that influenza vaccines were low to moderately effective, probably due to a mismatch between circulating and vaccine strains.Palabras clave
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Vacunas contra la Influenza
/
Gripe Humana
/
Subtipo H1N1 del Virus de la Influenza A
/
Subtipo H3N2 del Virus de la Influenza A
Tipo de estudio:
Observational_studies
/
Risk_factors_studies
Límite:
Adolescent
/
Adult
/
Aged
/
Aged80
/
Animals
/
Child
/
Child, preschool
/
Female
/
Humans
/
Infant
País como asunto:
Europa
Idioma:
En
Año:
2019
Tipo del documento:
Article