B and T cell responses to the BNT162b2 COVID-19 mRNA vaccine are not impaired in germ-free or antibiotic-treated mice

As reviewed by us recently, an increasing number of studies suggest that the gut microbiota is an important regulator of immune responses to vaccination. Consistent with these data, several recent clinical studies, including three published in Gut, uncover correlations between the composition of the faecal/gut microbiota and antibody responses to different COVID-19 vaccines. Additionally, recent antibiotic usage has also been associated with a lower seroconversion rate following BNT162b2 vaccination. These studies suggest that the gut microbiota plays a significant role in regulating optimal immune responses to COVID-19 vaccines. Despite these important studies, the causal and mechanistic links between the gut microbiota and responses to COVID-19 vaccines remain to be elucidated...