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

Inclusion Criteria: * Aged 6 months for Cohort 1 and 12 months for Cohort 2 on the day of inclusion ("6 months" means from the day of the 6-month birthday to the day before the 7-month birthday and "12 months" means from the day of the 12-month birthday to the day before the 13-month birthday) * Participants who are healthy as determined by medical evaluation including medical history and physical examination * For Cohort 1: Infant received doses of vaccines containing hepatitis B, diphtheria, tetanus, pertussis, Haemophilus influenzae type B (Hib), and inactivated poliovirus vaccine (IPV) antigens, with Advisory Committee on Immunization Practice (ACIP) recommended vaccines. The last dose(s) of these vaccines must be at least 28 days before the first study visit * Infant received the recommended doses of a recommended pneumococcal conjugate vaccine (as per local schedule) at least 28 days before the first study visit. Exclusion Criteria: * Known or suspected congenital or acquired immunodeficiency; or receipt of immunosuppressive therapy, such as anti-cancer chemotherapy or radiation therapy, within the preceding 6 months; or long-term systemic corticosteroid therapy (prednisone or equivalent for more than 2 consecutive weeks within the past 3 months) * Known previous infection with diphtheria, tetanus, Hib, measles, mumps, rubella, rotavirus, pneumococcus, polio, hepatitis B virus * Known systemic hypersensitivity to any of the study intervention components, or history o…