A Phase 2 Clinical Trial of VLA1553 in Healthy Children Aged 1 to 11 Years

NCT06106581 | Completed Phase 2 DMC FDA Drug

• 1 other identifier: VLA1553-221
• Study Type: interventional
• Target: 304
• Locations: 2 countries
• Sites: 3

Brief Summary

This is a multicenter, prospective, randomized, observer-blinded, three arm, phase 2 clinical trial evaluating the full dose formulation of VLA1553, half dose formulation of VLA1553 and control. At least 300 male and female healthy children aged 1 to 11 years will be enrolled and the overall distribution of participants will be 2:2:1 to the two VLA1553 dose groups (n=120 each) or control (n=60).

Conditions

Chikungunya Virus Infection

Outcome Measures

Primary Outcomes (4)

• Frequency of solicited injection site reactions

  within 14 days post-vaccination

• Severity of solicited injection site reactions

  within 14 days post-vaccination

• Frequency of systemic reactions

  within 14 days post-vaccination

• Severity of systemic reactions

  within 14 days post-vaccination

Secondary Outcomes (7)

• Frequency of any adverse event (AE)

  within 28 days post-vaccination

• Severity of any adverse event (AE)

  within 28 days post-vaccination

• Frequency of unsolicited AE

  until Month 6 (Day 180) and Month 12 (Day 365) post-vaccination

• Severity of unsolicited AE

  until Month 6 (Day 180) and Month 12 (Day 365) post-vaccination

• Frequency of any serious adverse event (SAE)

  until Month 6 (Day 180) and Month 12 (Day 365) post-vaccination

Study Arms (3)

VLA1553 full dose

EXPERIMENTAL

Biological: VLA1553 full dose

VLA1553 half dose

EXPERIMENTAL

Biological: VLA1553 half dose

Control

ACTIVE COMPARATOR

Single intramuscular vaccination on Day 1 with Nimenrix (Men ACWY vaccine), a conjugate vaccine indicated for the active immunization

Biological: Control

Interventions

VLA1553 full dose BIOLOGICAL

Single intramuscular vaccination on Day 1 with VLA1553 full dose, a lyophilized live-attenuated Chikungunya vaccine candidate

VLA1553 full dose

VLA1553 half dose BIOLOGICAL

Single intramuscular vaccination on Day 1 with VLA1553 half dose, a lyophilized live-attenuated Chikungunya vaccine candidate

VLA1553 half dose

Control BIOLOGICAL

Nimenrix

Control

Eligibility Criteria

• Age: 1 Year - 11 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Child (0-17)

You may qualify if:

• Male or female healthy children aged 7 to 11 years for Stratum A, 3 to 6 years for Stratum B and 1 to 2 years for Stratum C at the time of vaccination;
• Written informed consent by the participant's parent(s)/Legally Acceptable Representative(s) ((LAR(s)), according to local requirements, and written informed assent of the participant, if applicable;

You may not qualify if:

• Participant who is IgM+/IgG- does not qualify for participation in this trial.
• Participant is taking medication or other treatment for unresolved symptoms attributed to a previous CHIKV infection; or has participated in a clinical trial involving an investigational CHIKV vaccine;
• Participant has an acute or recent infection (and who is not symptom-free in the week prior to the Screening Visit (Visit 0)

Sponsors & Collaborators

• Valneva Austria GmbH: lead

Study Sites (3)

Fundacion Dominicana de Perinatologia Fundacion Probebe

Santo Domingo, Gazcue, Dominican Republic

Location

Instituto Dermatologico y Cirugia de la Piel "Dr Huberto Bogaert Diaz" IDCP

Santo Domingo, 10306, Dominican Republic

Location

Inversiones en Investigacion Medica INVERIME

Tegucigalpa, Honduras

Location

MeSH Terms

Conditions

Chikungunya Fever

Condition Hierarchy (Ancestors)

Alphavirus Infections; Arbovirus Infections; Vector Borne Diseases; Infections; Mosquito-Borne Diseases; Virus Diseases; Togaviridae Infections; RNA Virus Infections

Study Officials

• Valneva Clinical Development

  Valneva Austria GmbH

  STUDY CHAIR

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: October 24, 2023
• First Posted: October 30, 2023
• Study Start: December 18, 2023
• Primary Completion: July 31, 2024
• Study Completion: July 2, 2025
• Last Updated: August 8, 2025

Record last verified: 2025-08

Data Sharing

• IPD Sharing: Will share

Locations

HO (1); DO (2)