A Study on the Immunogenicity and Safety of 3 Different Dose Concentrations of a Respiratory Syncytial Virus Vaccine in Infants and Toddlers

This study was a Phase III, parallel group, randomized, observer blind, placebo controlled, multi-national, multi-center, multi-arm study conducted in 42 healthy children enrolled at 6 months to \<22 months of age. The purpose of the study was to evaluate the non-inferiority of the immune response of the lower dose (LD) when compared to the standard dose (SD) respiratory syncytial virus infant and toddler (RSVt) vaccine and the safety of the LD, SD and high dose (HD) vaccine in preterm born children and of the HD vaccine in full term born children administered by intranasal route and compared to placebo.