A Trial to Evaluate the Safety and Immunogenicity of VLA1553 in Healthy Children

NCT07133178 | Withdrawn Phase 3 DMC FDA Drug

• 1 other identifier: VLA1553-322
• Study Type: interventional
• Target: N/A
• Locations: 0 countries
• Sites: N/A

Brief Summary

VLA1553-322 is a multicenter, prospective, randomized, double-blind, phase 3 clinical trial evaluating VLA1553 in comparison to a comparator (Nimenrix®) for each stratum (age group). At least 3,000 male and female healthy children aged 1 to 11 years will be enrolled and randomized 3:1 to either VLA1553 (n=2,250) or comparator (Nimenrix®) (n=750).

Conditions

Chikungunya Virus Infection

Outcome Measures

Primary Outcomes (1)

• The proportion of participants with a seroresponse as defined by μPRNT50 for baseline negative participants

  28 days post-vaccination

Secondary Outcomes (13)

• Immune response as measured by CHIKV-specific neutralizing antibody titers as determined by μPRNT assay

  on Day 1, Day 15, Day 29, Day 85, Day 180, and Month 12 (Day 365)

• Proportion of participants with seroresponse as determined by μPRNT assay

  on Day 15, Day 29, Day 85, Day 180 and Month 12 (Day 365)

• Proportion of participants with seroconversion as compared to baseline as determined by μPRNT assay

  on Day 15, Day 29, Day 85, Day 180 and Month 12 (Day 365)

• Fold increase of CHIKV-specific neutralizing antibody titers determined by μPRNT assay as compared to baseline

  on Day 15, Day 29, Day 85, Day 180 and Month 12 (Day 365)

• Proportion of participants reaching an at least 4-fold, 8-fold, 16-fold, or 64-fold increase in CHIKV-specific neutralizing antibody titers compared to baseline as measured by μPRNT assay

  on Day 15, Day 29, Day 85, Day 180 and Month 12 (Day 365)

Study Arms (2)

VLA1553

EXPERIMENTAL

VLA1553

Biological: VLA1553

Control

ACTIVE COMPARATOR

Nimenrix will be used as Comparator

Biological: Control

Interventions

VLA1553 BIOLOGICAL

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

VLA1553

Control BIOLOGICAL

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

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 obtaining participant informed consent / assent;
• 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 is generally healthy as determined by the Investigator's clinical judgement based on medical history, physical examination and screening laboratory tests;
• Participants in Stratum C (1 to 2 years) must be within the normal WHO growth and weight ranges for their age.
• Participant is seropositive for previous CHIKV exposure (i.e. IgM+ / IgG+ or IgM- / IgG+) or seronegative (i.e. IgM- / IgG-);
• If participant is of childbearing potential (e.g. after onset of menarche) and if involved in activities that could result in pregnancy:
• Female participant has a negative pregnancy test (in accordance with local regulations) at Screening (Visit 0) and Day 1 (Visit 1), respectively;
• Female participant has practiced an adequate method of contraception during at least the 30 days before Screening (Visit 0) and during the Screening period;
• Female/ male participant agrees to employ adequate birth control measures ) for the first three months post-vaccination (i.e. until Day 85, Visit 5).

You may not qualify if:

• Participant who is anti-CHIKV 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 both the Screening visit (Visit 0) and Visit 1;
• Participant has received another live virus vaccine within 28 days or inactivated / other vaccine within 14 days prior to vaccination in this trial or plans to receive a live virus vaccine within 28 days or inactivated vaccine / other within 14 days after vaccination; Whenever possible, standard of care vaccinations should be planned with the trial VLA1553 administration in mind.
• Participant has an ongoing medical history of or currently has acute or progressive, unstable, controlled or uncontrolled clinical condition (e.g., cardiovascular, respiratory, neurologic, psychiatric, or rheumatologic conditions) that poses a risk for participation in the trial, based on the Investigators clinical judgement. Examples include individuals with controlled, 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 has abnormal findings in any required trial investigations (including medical history, physical examination, and clinical laboratory) considered clinically relevant by the Investigator which pose a risk for participation in the trial based on his / her judgement;
• Participant has a history of immune-mediated or clinically relevant arthritis / arthralgia;
• The participant, their parent(s) / LAR(s) or siblings have a known HIV, hepatitis B or hepatitis C infection;
• Participant has a history of malignancy;
• Participant has a known or suspected defect of the immune system that can 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. Immuno-suppressive therapy is 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 are allowed.
• Participant has a history of any vaccine related contraindicating event (e.g., anaphylaxis, allergy to components of VLA1553 or Nimenrix®, or other known contraindications including febrile convulsions);
• Participant presents with clinical conditions representing severe bleeding disorders and medications interfering with blood clotting;
• Participant is pregnant (positive pregnancy test - in accordance with local regulations - at Screening or Visit 1, respectively) or is lactating at the time of enrollment or, for participants involved in activities potentially leading to pregnancy:
• female participants on unreliable contraception after onset of menarche
• male participant does not agree to employ adequate birth control measures during the first three months:

Sponsors & Collaborators

• Valneva Austria GmbH: lead

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 3
• 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: August 13, 2025
• First Posted: August 20, 2025
• Study Start: February 6, 2026
• Primary Completion (Estimated): December 1, 2026
• Study Completion (Estimated): November 1, 2027
• Last Updated: December 31, 2025

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will share