Pregnancy-related immune suppression leads to altered influenza vaccine recall responses

Clin Immunol. 2019 Nov:208:108254. doi: 10.1016/j.clim.2019.108254. Epub 2019 Aug 27.


Pregnancy is a risk factor for severe influenza infection. Despite achieving seroprotective antibody titres post immunisation fewer pregnant women experience a reduction in influenza-like illness compared to non-pregnant cohorts. This may be due to the effects that immune-modulation in pregnancy has on vaccine efficacy leading to a less favourable immunologic response. To understand this, we investigated the antigen-specific cellular responses and leukocyte phenotype in pregnant and non-pregnant women who achieved seroprotection post immunisation. We show that pregnancy is associated with better antigen-specific inflammatory (IFN-γ) responses and an expansion of central memory T cells (Tcm) post immunisation, but low-level pregnancy-related immune regulation (HLA-G, PIBF) and associated reduced B-cell antibody maintenance (TGF-β) suggest poor immunologic responses compared to the non-pregnant. Thus far, studies of influenza vaccine immunogenicity have focused on the induction of antibodies but understanding additional vaccine-related cellular responses is needed to fully appreciate how pregnancy impacts on vaccine effectiveness.

Keywords: Influenza; Pregnancy; Tolerance; Vaccination.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Antibodies, Viral / blood
  • Female
  • Humans
  • Immune Tolerance / immunology*
  • Immunogenicity, Vaccine / immunology*
  • Immunologic Memory / immunology*
  • Influenza Vaccines / immunology*
  • Pregnancy / immunology*


  • Antibodies, Viral
  • Influenza Vaccines