Mild and asymptomatic influenza B virus infection among unvaccinated pregnant persons: Implication for effectiveness of non-pharmaceutical intervention and vaccination to prevent influenza

Details

• Alternative Title:
  Vaccine
• Personal Author:
  Chen, Liling ; Levine, Min Z. ; Zhou, Suizan ; Bai, Tian ; Pang, Yuanyuan ; Bao, Lin ; Tan, Yayun ; Cui, Pengwei ; Zhang, Ran ; Millman, Alexander J. ; Greene, Carolyn M. ; Zhang, Zhongwei ; Wang, Yan ; Zhang, Jun
• Description:
  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.
  
  
• Subjects:
  Article Female Herpesviridae Infections Humans Influenza, Human Influenza A Virus, H3N2 Subtype Influenza B Virus Influenza Vaccines Influenza Virus Infection Pregnancy Seroconversion Vaccination

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• Source:
  Vaccine. 41(3):694-701
• Pubmed ID:
  36526503
• Pubmed Central ID:
  PMC10250188
• Document Type:
  Journal Article
• Funding:
  CC999999/ImCDC/Intramural CDC HHSUnited States/ ; U2G GH000018/GH/CGH CDC HHSUnited States/
• Volume:
  41
• Issue:
  3
• Collection(s):
  CDC Public Access
• Main Document Checksum:
  urn:sha256:6b6fcba847cc937d2288661c80801cb3bfacd5f16f04a651ff93d1fa00236af6
• Download URL:
  https://stacks.cdc.gov/view/cdc/129652/cdc_129652_DS1.pdf
• File Type:
  [PDF - 859.14 KB ]