Neonatal Vaccination: Challenges and Intervention Strategies.

BACKGROUND While vaccines have been tremendously successful in reducing the incidence of serious infectious diseases, newborns remain particularly vulnerable in the first few months of their life to life-threatening infections. A number of challenges exist to neonatal vaccination. However, recent advances in the understanding of neonatal immunology offer insights to overcome many of those challenges. OBJECTIVE This review will present an overview of the features of neonatal immunity which make vaccination difficult, survey the mechanisms of action of available vaccine adjuvants with respect to the unique features of neonatal immunity, and propose a possible mechanism contributing to the inability of neonates to generate protective immune responses to vaccines. METHODS We surveyed recent published findings on the challenges to neonatal vaccination and possible intervention strategies including the use of novel vaccine adjuvants to develop efficacious neonatal vaccines. RESULTS Challenges in the vaccination of neonates include interference from maternal antibody and excessive skewing towards Th2 immunity, which can be counteracted by the use of proper adjuvants. CONCLUSION Synergistic stimulation of multiple Toll-like receptors by incorporating well-defined agonist-adjuvant combinations to vaccines is a promising strategy to ensure a protective vaccine response in neonates.