CI

At a glance

ClinicalIndex Comparison Record
Phase 3Completed· 754 enrolled / 754 target
Drug / intervention
Active +1 morebiological
Likely dose
Active 0.5 mLfrom record
Structured eligibility isn't available for this trial yet — see the full criteria in the Eligibility tab below.

Standardized by ClinicalIndex from the ClinicalTrials.gov record · verify against the source.

Search/NCT04650399
NCT04650399Phase 3CompletedOn Track (14.3/mo)Completion was 39mo ago
CompareCT.gov

A Multicenter, Randomized, Controlled, Double Blinded Pivotal Study to Evaluate Safety and Immunogenicity of a Live-attenuated Chikungunya Virus Vaccine Candidate (VLA1553) in Adolescents Aged 12 Years to <18 Years

Butantan Institute·interventional·Posted Dec 2, 2020·Updated Jun 4, 2026

In Brief

A Phase 3 clinical trial evaluating Active and Placebo for Chikungunya. Completed, enrolled 754 participants across 10 sites.

Detailed Summary

This was a prospective, randomized, double-blinded, multicenter, pivotal study evaluating the full dose of VLA1553 (1 x10E4 TCID50 per dose) in comparison to a placebo control. The dose of VLA1553 or control was administered as single vaccination on Day 1. Overall, approximately 750 male and female participants aged 12 years to \<18 years were enrolled into the study. After completion of the trial, a Post Trial Access program was performed to offer the VLA1553 vaccine to all placebo recipients.

Study Details

Study Typeinterventional
Allocation--
Masking--
Primary Purpose--
ConditionsChikungunya
CountriesBrazil
CollaboratorsValneva Austria GmbH

Timeline

Phase 3CompletedFinished
202120222023202420252026
First PostedDec 2, 2020
Enrollment StartFeb 14, 2022
Primary CompletionMar 14, 2023
Study CompletionFeb 16, 2024
TodayJul 2, 2026
Enrollment to primary: 1.1 yearsPosted 5.6 years ago

Arms & Interventions

Activeexperimental

VLA1553

Biological: Active
Placeboplacebo_comparator

Placebo

Biological: Placebo

Interventions

Activebiological

Single intramuscular vaccination on Day 1 with VLA1553, a lyophilized live-attenuated Chikungunya vaccine candidate 1x10E4 TCID50 per dose (0.5 mL)

Placebobiological

Single intramuscular vaccination on Day 1 with Phosphate-Buffered Saline (PBS) as placebo (0.5 mL)