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.

中文翻译：

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怀孕相关的免疫抑制导致流感疫苗召回反应改变。

怀孕是严重流感感染的危险因素。尽管在免疫后达到了血清保护性抗体的效价，但与未怀孕的人群相比，较少的孕妇会减少流感样疾病的发生。这可能是由于怀孕中的免疫调节对疫苗功效的影响，导致免疫应答较差。为了理解这一点，我们调查了在免疫后获得血清保护的孕妇和非孕妇中的抗原特异性细胞应答和白细胞表型。我们显示，妊娠与更好的抗原特异性炎症（IFN-γ）反应和免疫后中央记忆T细胞（Tcm）的扩增有关，但与妊娠相关的免疫调节水平较低（HLA-G，PIBF）和相关的B细胞抗体维持率降低（TGF-β）表明，与非妊娠相比，免疫反应较差。迄今为止，流感疫苗免疫原性的研究集中在抗体的诱导上，但是需要了解其他与疫苗相关的细胞反应，以充分了解怀孕如何影响疫苗的有效性。