Modulation of immune responses to vaccination by the microbiota: implications and potential mechanisms

This Review discusses evidence from clinical studies and animal models regarding the effects of the gut microbiota on modulating immune responses to vaccination as well as the immunological mechanisms that potentially mediate these effects. 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.

Automated summary

The need for highly effective vaccines that induce robust and long-lasting immunity is increasingly apparent. The composition and function of the gut microbiota are now recognized as crucial factors modulating immune responses to vaccination. Targeted interventions towards the microbiota may hold potential in optimizing vaccine effectiveness.