Concluding remarks
Worldwide, infectious diseases cause death of > 2 million newborns and infants less than 6 months of age. Significant reduction of this burden will require development of early life vaccination, including vaccines effective when given at birth, the most reliable point of global healthcare contact. Based on animal and human studies, neonatal vaccination is feasible, but requires strong immune signals such as those provided by in vivo replication of attenuated agents, and perhaps by certain adjuvants. Advances in manipulating attenuated microbial strains and recent characterization of innate immune recognition pathways provide opportunities for developing novel delivery systems and/or adjuvants to meet this crucial challenge. Safety considerations will be paramount, but the large burden of early life infections coupled with the practicality of immunizing at birth provide strong motivation to pursue effective neonatal vaccines.