Mild and asymptomatic influenza B virus infection among unvaccinated pregnant persons: Implication for effectiveness of non-pharmaceutical intervention and vaccination to prevent influenza.
Vaccine
; 41(3): 694-701, 2023 01 16.
Article
en En
| MEDLINE
| ID: mdl-36526503
ABSTRACT
BACKGROUND:
We estimated symptomatic and asymptomatic influenza infection frequency in community-dwelling unvaccinated pregnant persons to inform risk communication.METHODS:
We collected residue sera from multiple antenatal-care blood draws during October 2016-April 2017. We determined influenza infection as seroconversion with ≥ 4-fold rise in antibody titers between any two serum samples by improved hemagglutinin-inhibition assay including ether-treated B antigens. The serology data were linked to the results of nuclei acid testing (rRT-PCR) based on acute respiratory illness (ARI) surveillance.RESULTS:
Among all participants, 43 %(602/1384) demonstrated serology and/or rRT-PCR evidenced infection, and 44 %(265/602) of all infections were asymptomatic. ARI-associated rRT-PCR testing identified only 10 %(61/602) of total infections. Only 1 %(5/420) of the B Victoria cases reported ARI and had a rRT-PCR positive result, compared with 33 %(54/165) of the H3N2 cases. Among influenza ARI cases with multiple serum samples, 19 %(11/58) had seroconversion to a different subtype prior to the illness.CONCLUSIONS:
The incidence of influenza B infection in unvaccinated pregnant persons is under-estimated substantially. Non-pharmaceutical intervention may have suboptimal effectiveness in preventing influenza B transmission due to the less clinical manifestation compared to influenza A. The findings support maternal influenza vaccination to protect pregnant persons and reduce consequent household transmission.Palabras clave
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Base de datos:
MEDLINE
Asunto principal:
Vacunas contra la Influenza
/
Infecciones por Herpesviridae
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Gripe Humana
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Vaccine
Año:
2023
Tipo del documento:
Article