The need for highly effective vaccines that induce robust and long-lasting immunity has never been more apparent. However, for reasons that are still poorly understood, immune responses to vaccination are highly variable between different individuals and different populations. Furthermore, vaccine immunogenicity is frequently suboptimal in the very populations who are at most risk from infectious disease, including infants, the elderly, and those living in low-income and middle-income countries. Although many factors have the potential to influence vaccine immunogenicity and therefore vaccine effectiveness, increasing evidence from clinical studies and animal models now suggests that the composition and function of the gut microbiota are crucial factors modulating immune responses to vaccination. In this Review, we synthesize this evidence, discuss the immunological mechanisms that potentially mediate these effects and consider the potential of microbiota-targeted interventions to optimize vaccine effectiveness.

对能够诱导强大而持久的免疫力的高效疫苗的需求从未如此明显。然而，由于目前尚不清楚的原因，不同个体和不同人群对疫苗接种的免疫反应差异很大。此外，对于最容易感染传染病的人群，包括婴儿、老年人以及生活在低收入和中等收入国家的人群，疫苗的免疫原性往往不是最佳的。尽管许多因素有可能影响疫苗的免疫原性，从而影响疫苗的有效性，但来自临床研究和动物模型的越来越多的证据表明，肠道微生物群的组成和功能是调节疫苗接种免疫反应的关键因素。在这篇综述中，我们综合了这些证据，讨论了可能介导这些影响的免疫机制，并考虑了针对微生物群的干预措施优化疫苗有效性的潜力。