NCT06705140

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

A Parallel Group, Phase III, Randomized, Observer Blind, Placebo Controlled, Multi Center, Multinational, Multi Arm Study to Demonstrate Non-inferiority of the Immune Response of a Low Dose Compared to the Standard Dose and to Evaluate the Safety of a Respiratory Syncytial Virus Vaccine in Infants and Toddlers (OPAL)

• Status: Terminated
• Phase: Phase 3
• Study type: Interventional
• Enrollment: 947 (actual)
• Sponsor: Sanofi Pasteur, a Sanofi Company · Industry
• Sex: All
• Age: 6 Months – 21 Months
• Healthy volunteers: Accepted

Summary

This study is a Phase III, parallel group, randomized, observer blind, placebo controlled, multi-national, multi-center, multi-arm study to be conducted in 947 healthy children enrolled at 6 months to \<22 months of age. The purpose of the study is 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.

Detailed description

The study duration is approximately 8 months for each participant, including the 6 months safety follow-up phone call after the second study intervention administration.

Conditions

• RSV Immunisation

Interventions

Type	Name	Description
BIOLOGICAL	Low Dose (LD) RSVt vaccine	Pharmaceutical form: Liquid for nasal spray Route of administration: Intranasal
BIOLOGICAL	Standard Dose (SD) RSVt vaccine	Pharmaceutical form:Liquid for nasal spray-Route of administration:Intranasal
BIOLOGICAL	High Dose (HD) RSVt vaccine	Pharmaceutical form:Liquid for nasal spray-Route of administration:Intranasal
BIOLOGICAL	Placebo	Pharmaceutical form:Liquid for nasal spray-Route of administration:Intranasal

Timeline

• Start date: 2024-11-25
• Primary completion: 2025-06-11
• Completion: 2025-06-11
• First posted: 2024-11-26
• Last updated: 2026-02-03

Locations

4 sites across 2 countries: Dominican Republic, Honduras

Regulatory

• FDA-regulated drug study