Abstract
Respiratory viral infections in infants and young children frequently cause illness that can easily progress to hospitalization and death. There are currently no licensed vaccines to prevent respiratory viral disease in children younger than 6 months, reflecting safety concerns and the difficulty in inducing effective immune responses in infants. This review discusses vaccines that have been developed, or are currently being developed, against influenza and respiratory syncytial virus, with a focus on studies performed to demonstrate their safety and efficacy, and the impact of immunologic immaturity and maternal antibodies on the infant response to vaccines.