Co-administration Study of an Investigational Live-Attenuated Respiratory Syncytial Virus Vaccine in Infants and Toddlers

This study is a Phase III, randomized, single-blind, placebo-controlled, multi-center study to be conducted in healthy infants and toddlers which will be enrolled at approximately 6 months of age (Cohort 1) and approximately 12 months of age (Cohort 2). The primary objective of the study will be to assess non-inferiority of the RSV infant and toddler (RSVt) vaccine antibody response when administered concomitantly with routine pediatric vaccines at 6 months of age (Diphtheria and Tetanus Toxoids and Acellular Pertussis, Inactivated Poliovirus, Haemophilus b Conjugate and Hepatitis B Vaccine \[Vaxelis® or Pentacel® and Recombivax HB®\] Prevnar 20®, and RotaTeq®), and 12 months of age (M-M-R II, VARIVAX, and Prevnar 20 or per local country recommendations) compared to when administered non-concomitantly.