A Phase 1/2, Randomized, Observer-Blind, Active-Controlled, Age De-escalation, Dose Combination Ranging Study to Assess the Safety and Immunogenicity of Co-administered Novel Live Attenuated Trivalent Oral Poliomyelitis Vaccine in Healthy Adults, Young Children, and Neonates and Co-administered Novel Live Attenuated Monovalent Oral Poliomyelitis Vaccines 1 and 2 in Neonates in Bangladesh
The main objectives of this study are to : * evaluate the safety and tolerability of trivalent novel oral poliovirus vaccines (tnOPV) in healthy adults, young children, and neonates, relative to those receiving control vaccines; * evaluate the safety and tolerability of combined novel oral poliovirus vaccine type 1 (nOPV1) + novel oral poliovirus vaccine type 2 (nOPV2) in neonates, relative to those receiving the bivalent (types 1 and 3) oral poliovirus vaccine (bOPV) control. * compare type-specific cumulative seroconversion rates of poliovirus neutralizing antibody (NAb) titers, among all tnOPV dose combinations, following 4 vaccinations in healthy neonates; * evaluate the type-specific cumulative seroconversion rate of poliovirus NAb titers among healthy neonates following 4 doses of combined nOPV1+nOPV2.
• Healthy, as defined by the absence of any clinically significant medical condition or congenital anomaly as determined by medical history, physical examination, and clinical assessment of the investigator.
• Participant or parent of the participant is willing and able to provide written informed consent prior to performance of any study-specific procedure.
• Resides and plans to remain in study area and participants and parent, when applicable, understands and is able and willing to adhere to all study visits and procedures (as evidenced by a signed informed consent form \[ICF\] and assessment by the investigator).
• Males or females, from 18 to 45 years of age (inclusive) at the time of enrollment.
• If female and of childbearing potential\*, not breastfeeding and not pregnant (based on a negative urine pregnancy test at screening and a negative urine pregnancy test during the 24 hours prior to any study vaccination \[if screening occurs within 24 hours prior to vaccination, a single negative pregnancy test is acceptable\]), agreeing to not become pregnant through other means (e.g., artificial insemination and IVF) and have repeated pregnancy tests prior to any study vaccination, and having practiced adequate contraception\*\* for 30 days prior to first study vaccination and willing to continue using adequate contraception consistently for at least 90 days after the last study vaccination.
• Born and raised in Bangladesh in 1990 or later; if born before 1990 or not born and raised in Bangladesh, has documentation of a complete poliomyelitis immunization series containing OPV or IPV.
• Male or female child from 1 to less than 5 years of age at the time of enrollment (from the first birthday up to the day prior to the fifth birthday).
• Based on documentation, previously received a 3 or 4 dose primary poliomyelitis immunization series containing bOPV ± IPV, with last dose received more than 3 months prior to initial study vaccination.
• Male or female newborn neonate (day of birth+ 3-day window), at the time of initial study vaccination.
⁃ Prior to study vaccination has received no doses of IPV or OPV or rotavirus vaccine, based upon documentation or parental history.
⁃ Agreement to receive polio EPI vaccines under a modified schedule.