Respiratory Syncytial Virus Toddler vaccine (Sanofi Pasteur)

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.

This study is a phase III, randomized, observer-blind, placebo-controlled, multinational, multi-center study to be conducted in approximately 6300 children 6 months to < 22 months of age. The purpose of the study is to evaluate the efficacy, immunogenicity, and safety of Respiratory Syncytial Virus Toddler (RSVt) vaccine administered by intranasal route compared to placebo.
Eligible participants will be randomized in a 1:1 ratio to receive 2 intranasal administrations of either the RSVt vaccine or placebo.
Study duration will be 24 months for each participant. The safety follow-up will start after the first vaccination and up to the end of the study.