Summary
The immune system of young infants exhibits profound alterations compared to that of older children and adults. Notable among these are lower responses to TLR engagement, reduced dendritic cell maturation, reduced Tfh responses, and a strong Th2 bias. While proposed to be beneficial for establishment of the microbiome and preventing untoward inflammatory responses, these alterations hamper the ability to respond to vaccines. As a result, infants are poor at mounting protective antibody responses following vaccination with standard seasonal influenza vaccines. Consequently, these vaccines are n
