NCT07002060

Phase 3 Randomized, Modified Double-blind, Active-controlled Safety Study on vYF in Adults

A Phase 3 Randomized, Modified Double-blind, Active-controlled Study to Assess the Safety of vYF, Yellow Fever Vaccine, in Adults Aged 18 Years up to 60 Years

• Status: Completed
• Phase: Phase 3
• Study type: Interventional
• Enrollment: 640 (actual)
• Sponsor: Sanofi · Industry
• Sex: All
• Age: 18 Years – 59 Years
• Healthy volunteers: Accepted

Summary

The purpose of this study is to assess the safety of vYF (investigational vaccine) compared to the safety of YF-VAX (YF licensed vaccine) in adults aged 18 years up to 60 years. Study details include: * The study duration will be up to approximately 6 months. * One single dose of the study intervention (vYF or YF-VAX) will be administered subcutaneously at the 1st visit. * The visit(V) frequency will be Day(D) 01 (V01) and D29 (V02). Two telephone calls will be planned at D15 and Month(M)6. Number of Participants: A total of 640 participants are expected to be included in the study in a 3:1 ratio (vYF: YF-VAX): Group 1: vYF; N=480 Group 2: YF-VAX; N=160 Study Arms and Duration: Randomized, active control (YF-VAX). 6 months duration per participants. Eligible participants will be randomized in a 3:1 ratio to receive, subcutaneously, a single dose of vYF or YF-VAX vaccines on D01.

Conditions

• Yellow Fever Immunization

Interventions

Type	Name	Description
BIOLOGICAL	Yellow fever vaccine (live)	Powder and solvent for solution for injection Subcutaneous
BIOLOGICAL	YF vaccine (live)	Powder and diluent for suspension for injection Subcutaneous

Timeline

• Start date: 2025-05-22
• Primary completion: 2026-01-20
• Completion: 2026-01-20
• First posted: 2025-06-03
• Last updated: 2026-02-02

Locations

7 sites across 1 country: United States

Regulatory

• FDA-regulated drug study