Introduction: High variance is associated with influenza vaccine effectiveness (VE). Accumulating evidence suggests that preexisting influenza-specific immunity results in the variance in VE and skews overall immune response to vaccination. Nevertheless, the investigation of preexisting immunity is highly limited due to the lack of proper methodology to explore the complex individual immune history.Areas covered: Retrospective observational studies have shown that the preexisting influenza specific immunity influences on VE. To simplify a discussion, we summarized important findings from the observational studies based on the transition of the individual immune history: the first exposure to influenza virus, the first vaccination, and repetitive exposure throughout life. We also discussed the prospectus of pre-immunized animal models to investigate the interaction between preexisting immunity and vaccine efficacy.Expert opinion: A better understanding in the underlying mechanisms on preexisting immunity is critical to improve VE and to help develop novel vaccine strategies. Using animals pre-immunized with historical influenza strains is a promising approach to verify the underlying immunologic mechanism of interaction between preexisting immunity and vaccine antigen. Also, pre-immunized animal models will be better able to evaluate the efficacy of novel vaccine strategies than naïve animals.

中文翻译：

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预先存在的流感特异性免疫力和疫苗效力。

简介：高差异与流感疫苗效力（VE）相关。越来越多的证据表明，预先存在的流感特异性免疫会导致VE变异，并使总体免疫反应对疫苗接种产生偏倚。然而，由于缺乏探索复杂的个体免疫史的适当方法，对已有免疫的研究非常有限。覆盖范围：回顾性观察研究表明，已有流感特异性免疫对VE有影响。为简化讨论，我们基于个人免疫史的转变总结了观察性研究的重要发现：首次暴露于流感病毒，首次接种疫苗以及一生中反复暴露。我们还讨论了预先免疫动物模型的说明书，以研究预先存在的免疫力和疫苗功效之间的相互作用。专家意见：更好地了解预先存在的免疫力的潜在机制对于改善VE和帮助制定新的疫苗策略至关重要。使用经历史流感病毒株预免疫的动物是一种有前途的方法，可用于验证预先存在的免疫力和疫苗抗原之间相互作用的潜在免疫学机制。同样，预免疫的动物模型比幼稚的动物将能够更好地评估新型疫苗策略的功效。更好地了解已有免疫的基本机制对于改善VE和帮助开发新的疫苗策略至关重要。使用经历史流感病毒株预免疫的动物是一种有前途的方法，可用于验证预先存在的免疫力和疫苗抗原之间相互作用的潜在免疫学机制。同样，预免疫的动物模型比幼稚的动物将能够更好地评估新型疫苗策略的功效。更好地了解已有免疫的基本机制对于改善VE和帮助开发新的疫苗策略至关重要。使用经历史流感病毒株预免疫的动物是一种有前途的方法，可用于验证预先存在的免疫力和疫苗抗原之间相互作用的潜在免疫学机制。同样，预免疫的动物模型比幼稚的动物将能够更好地评估新型疫苗策略的功效。