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

NCT06106581 | Completed Phase 2 Results 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)

• Number of Participants With Solicited Injection Site Reactions

  Frequency and severity of solicited injection site and solicited systemic reactions within 14 days post-vaccination.

  within 14 days post-vaccination

• Severity of Solicited Injection Site Reactions

  within 14 days post-vaccination

• Number of Participants With Solicited Systemic Reactions

  within 14 days post-vaccination

• Severity of Solicited Systemic Reactions

  within 14 days post-vaccination

Secondary Outcomes (27)

• Number of Participants With Any Adverse Event (AE)

  within 28 days post-vaccination

• Severity of Any Adverse Event (AE)

  within 28 days post-vaccination

• Number of Participants With 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

• Number of Participants With 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;
• Participant was seropositive for previous CHIKV exposure (i.e., IgM+/IgG+ or IgM-/IgG+) or seronegative (i.e., IgM-/IgG-); or participants with any borderline IgM or IgG element (IgM borderline/IgG-, IgM-/IgG borderline, or IgM borderline/IgG borderline were mapped to seronegative group; participants with enzyme-linked immunosorbent assay (ELISA) result IgM borderline/IgG+ were mapped to seropositive group);

You may not qualify if:

• Participant was IgM+/IgG- does not qualify for participation in this trial.
• Participant was taking medication or other treatment for unresolved symptoms attributed to a previous CHIKV infection; or had participated in a clinical trial involving an investigational CHIKV vaccine;
• Participant had an acute or recent infection (and was not symptom-free in the week prior to the Screening Visit (Visit 0))
• Participant had received another live virus vaccine within 28 days or inactivated vaccine (includes messenger ribonucleic acid \[mRNA\] vaccines) within 14 days prior to vaccination in this trial or planned to receive a live virus vaccine within 28 days or inactivated vaccine within 14 days after vaccination;
• Participant had abnormal findings in any required trial investigations (including medical history, physical examination, and clinical laboratory) considered clinically relevant by the Investigator which posed a risk for participation in the trial based on his/her judgment;
• Participant had an ongoing medical history of or currently had acute or progressive, unstable or uncontrolled clinical conditions (e.g., cardiovascular, respiratory, neurologic, psychiatric, or rheumatologic conditions) that posed a risk for participation in the trial, based on Investigator's clinical judgment. Examples included individuals with poorly controlled or unstable disease, ongoing suspected or active inflammation, or poor compliance with pharmacologic treatment, or presence of high-risk comorbidities (e.g., significant cardiopulmonary disease);
• Participant had a history of immune-mediated or clinically relevant arthritis/arthralgia;
• Participant had a known or suspected defect of the immune system that could be expected to influence the immune response to the vaccine, such as Participants with congenital or acquired immunodeficiency, including infection with HIV, status post organ transplantation or immuno- suppressive therapy within 4 weeks prior to Visit 1. Immunosuppressive therapy was defined as administration of chronic (longer than 14 days) prednisone or equivalent ≥0.05 mg/kg/day within 4 weeks prior to trial entry, radiation therapy or immunosuppressive cytotoxic drugs/ monoclonal antibodies in the previous 3 years; topical and inhaled steroids were allowed.
• Participant had a history of any vaccine-related contraindicating event (e.g., anaphylaxis, allergy to components of the vaccine or the control vaccine, other known contraindications including febrile convulsions);
• Participant presented with clinical conditions representing severe bleeding disorders and medications interfering with blood clotting;
• Participant received blood-derived products (e.g. plasma) within 180 days prior to vaccination in this trial;
• Participant had participated in another clinical trial involving an investigational medicinal product (IMP) or device within 30 days prior to vaccination or was scheduled to participate in another clinical trial involving an IMP, or device during the course of this trial;
• Participant had any condition that, in the opinion of the Investigator, could compromise the participant's well-being, might interfere with evaluation of trial endpoints, or would limit the participant's ability to complete the trial;
• Participant/ Participant's parent(s)/LAR(s) was/were a member of the team conducting the trial or in a dependent relationship with one of the trial team members. Dependent relationships included close relatives (i.e., children, partner/spouse, siblings, parent(s)/LAR\[s\]) as well as employees of the Investigator or site personnel conducting the trial.

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

Related Publications (1)

• Weisova P, Scheiblauer S, Ecker J, Schneider M, Hochreiter R, Bitzer A, Kosulin K, Schoengrundner P, Fuchs U, Rodeles L, Mazara S, Donastorg Y, Rivera S, Wressnigg N, Dubischar K, Buerger V, Eder-Lingelbach S, Jaramillo JC. Live-attenuated chikungunya vaccine in children: a randomized phase 2 trial. Nat Med. 2026 Feb;32(2):561-571. doi: 10.1038/s41591-025-04197-2. Epub 2026 Feb 6.

  PMID: 41652122 DERIVED

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

Results Point of Contact

• Title: Clinical Strategy Manager
• Organization: Valneva Austria GmbH

office@valneva.com

+43 1 206 20

Study Officials

• Valneva Clinical Development

  Valneva Austria GmbH

  STUDY CHAIR

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: Yes

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 13, 2026
• Results First Posted: August 13, 2026

Record last verified: 2025-08

Data Sharing

• IPD Sharing: Will share

Locations

HO (1); DO (2)