Immune response to vaccine adjuvants during the first year of life

Subunit vaccine formulations often include adjuvants that primarily stimulate innate immune cells. While young infants represent the major target population for vaccination, effective immunization in this age group remains a challenge. Many parameters of innate immune responses differ quantitatively and qualitatively from newborns to infants and adults, revealing a highly regulated developmental program. Herein, we discuss the potential implications of innate immune ontogeny for the activity of adjuvants contained in licensed infant vaccines, as well as future directions for rational design of adjuvanted vaccines for this age group.

► We comprehensively reviewed mechanisms of action of licensed adjuvants.
► We examined the changes of adjuvant responses with age in early life.
► We juxtaposed the current knowledge with safety considerations.
► We point to the need for targeted investigations of adjuvant activity early in life.