NCT07254702

Prospective Safety Cohort Study After VLA1553 Vaccination in Municipalities Selected for Participation in the VLA1553 Pilot Vaccination Strategy in Brazil

Prospective Safety Cohort Study VLA1553-406

• Status: Enrolling By Invitation
• Phase: —
• Study type: Observational
• Enrollment: 5,000 (estimated)
• Sponsor: Valneva Austria GmbH · Industry
• Sex: All
• Age: 18 Years
• Healthy volunteers: Accepted

Summary

This is an observational study with primary data collection, which will combine a prospective safety cohort study and an SCRI study.

Detailed description

This prospective safety cohort study will be conducted in selected Brazilian municipalities participating in a pilot vaccination strategy. A total of 5,000 participants will be recruited. The primary objective is to estimate the incidence rates of a predefined set of AEs which constitute safety concerns. The secondary objectives are to measure the relative risk associated with VLA1553 administration for a predefined set of AEs which constitute safety concerns, and to assess the frequency of occurrence of any collected AE which are medically attended or meet the criteria of seriousness This study also aims to investigate VLA1553's safety in underrepresented populations by collecting all AEs, not just AEs which constitute safety concerns.

Conditions

• Chikungunya Virus Infection

Interventions

Type	Name	Description
BIOLOGICAL	Live-attenuated CHIKV vaccine VLA1553	Non-interventional study: VLA1553 is used in the pilot vaccination strategy which will start along with this observational study.

Timeline

• Start date: 2026-02-02
• Primary completion: 2026-10-31
• Completion: 2027-02-28
• First posted: 2025-11-28
• Last updated: 2026-02-11

Locations

4 sites across 1 country: Brazil