Chikungunya Virus InfectionPhase 2NCT06106581
A Phase 2 Clinical Trial of VLA1553 in Healthy Children Aged 1 to 11 Years
A Phase 2 study testing VLA1553 full dose and VLA1553 half dose in people with Chikungunya Virus Infection, run by Valneva Austria GmbH at 3 sites in 2 countries.
Trial 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. Read more about this study
- Who is it for?
- Ages 1 year to 11 yearsHealthy volunteers can take part
- Conditions the study is for
- Chikungunya Virus Infection
- What is being tested?
- VLA1553 full dose and VLA1553 half dose
- Type of treatment
- Vaccines, Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 304 participants
- Where
- 3 sitesin 2 countries
- Study dates
- 18 Dec 2023to 2 Jul 2025
- Phase
- Phase 2
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 1 year to 11 years
- All sexes
- Healthy volunteers accepted
- Child
Who may be able to join
- 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);
Who cannot join
- 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);
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- 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.
Trial locations and contacts
3 sites in 2 countries.
3 sites in 2 countries
Dominican Republic2 sites
Fundacion Dominicana de Perinatologia Fundacion Probebe
Santo Domingo, Gazcue
Instituto Dermatologico y Cirugia de la Piel "Dr Huberto Bogaert Diaz" IDCP
Santo Domingo, 10306
About this study
Official title: A Randomized, Observer-blinded, Dose Response Phase 2 Trial to Assess the Safety and Immunogenicity of Two Different Dose Levels of a Live-attenuated Chikungunya Virus Vaccine (VLA1553) in Healthy Children Aged 1 to 11 Years
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).
Read the detailed description
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 (Nimenrix, a tetravalent meningococcal vaccine - Men ACWY).
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 (Nimenrix) (n=60).
As a safety precaution measure, the first 30 sentinel participants will be enrolled into the trial in an open-label fashion according to an age step down scheme.
After sentinel analysis, participants will be enrolled in a blinded, randomized manner into three Trial Arms. Within each treatment arm participants will be stratified into three age strata:
Stratum A: 7 to 11 years -children from their 7th birthday until the day before their 12th birthday.
Stratum B: 3 to 6 years - children from their 3rd birthday until the day before their 7th birthday.
Stratum C: 1 to 2 years - children from their 1st birthday until the day before their 3rd birthday.
Age strata for the VLA1553 treatment arms are targeted to be equal in size, i.e., approximately 40 per age stratum.
- Conditions
- Chikungunya Virus Infection
- Being tested
- VLA1553 full dose, VLA1553 half dose, Control
- Medical subject headings
- Chikungunya Fever
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
VLA1553 full doseBiological
Single intramuscular vaccination on Day 1 with VLA1553 full dose, a lyophilized live-attenuated Chikungunya vaccine candidate
VLA1553 half doseBiological
Single intramuscular vaccination on Day 1 with VLA1553 half dose, a lyophilized live-attenuated Chikungunya vaccine candidate
ControlBiological
Nimenrix
| Study group | Role | What they receive |
|---|---|---|
| VLA1553 full dose | Experimental | Not described Receives: Biological: VLA1553 full dose |
| VLA1553 half dose | Experimental | Not described Receives: 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 Receives: Biological: Control |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of Participants With Solicited Injection Site Reactions
Frequency and severity of solicited injection site and solicited systemic reactions within 14 days post-vaccination.
Measured: within 14 days post-vaccination
Severity of Solicited Injection Site Reactions
Measured: within 14 days post-vaccination
Number of Participants With Solicited Systemic Reactions
Measured: within 14 days post-vaccination
Severity of Solicited Systemic Reactions
Measured: within 14 days post-vaccination
Secondary outcomes (27)
Number of Participants With Any Adverse Event (AE)
Measured: within 28 days post-vaccination
Severity of Any Adverse Event (AE)
In the Outcome measure "Severity of any AE", subjects may be represented in more than one AE category. Therefore, the total number of subjects with any AE may be lower than the sum of the numbers of subjects in the individual AE categories (solicited / unsolicited AE).
Measured: within 28 days post-vaccination
Number of Participants With of Unsolicited AE
Measured: until Month 6 (Day 180) and Month 12 (Day 365) post-vaccination
Severity of Unsolicited AE
Measured: until Month 6 (Day 180) and Month 12 (Day 365) post-vaccination
Number of Participants With Any Serious Adverse Event (SAE)
Measured: until Month 6 (Day 180) and Month 12 (Day 365) post-vaccination
Number of Participants With Any Early Onset Adverse Event of Special Interest (AESI)
Early onset AESI were defined as:
- Fever (≥ 38.0 °c / 100.4 °f,) AND
- symptoms suggesting acute (poly)arthralgia/arthritis, myalgia, neurological symptoms (e.g., for meningoencephalitis, acute encephalitis, headache, seizures), back pain, lymphadenopathy, cardiac or ocular symptoms (e.g., for uveitis and retinitis); OR one or more of the following signs and symptoms: macular to maculopapular rash (sometimes with cutaneous pruritus [foot plant]), pigmentary changes, bullous rash/ skin blistering, purpura, ecchymosis and
- Onset of symptoms 2 to 21 days after vaccination AND
- Duration of event ≥ 3 days.
Measured: 2 to 21 days post-vaccination
Severity of Any Early Onset Adverse Event of Special Interest (AESI)
Measured: 2 to 21 days post-vaccination
Number of Participants With Any Late Onset Adverse Event of Special Interest (AESI)
Measured: Starting 22 days post-vaccination until end of trial, 12 months post-vaccination
Severity of Any Late Onset Adverse Event of Special Interest (AESI)
Measured: Starting 22 days post-vaccination until end of trial, 12 months post-vaccination
Assessment of Viremia on Days 1, 4, 8 and 15
Number of participants with viremic results, including quantifiable results and results below LLOQ, by visit and by pooled trial arm. Day 29 was only tested, if Day 15 was tested positive.
Viremia is measured in genome copy equivalents per milliliter (GCE/mL). All quantifiable results and results below LLOQ (< 3214.4 GCE/mL), but above the LOD, are considered "viremic". A result of "not detected" or below LOD (<1071,4 GCE/mL) is included as "non-viremic".
Measured: on Days 1, 4, 8 and 15 and beyond as applicable
Immune Response in Baseline Seronegative Participants as Measured by CHIKV-specific Neutralizing Antibody Titers
Immune Response provided by Geometric Mean Titers (GMTs) in Baseline Seronegative Participants pooled by Trial Arm up to 12 months post vaccination.
Measured: on Day 1, Day 15, Day 29, Day 85, Day 180 and Month 12 post-vaccination
Immune Response as Measured by CHIKV-specific Neutralizing Antibody Titers by Age Group and Trial Arm.
Immune Response provided by Geometric Mean Titers (GMTs) by Visit, by Age Group and Trial Arm up to 12 months post vaccination.
Measured: on Day 1, Day 15, Day 29, Day 85, Day 180 and Month 12 post-vaccination
Immune Response Measured by CHIKV-specific Neutralizing Antibody Titers Pooled by Dose
Immune Response provided by Geometric Mean Titers (GMTs) by Visit, pooled by Trial Arm up to 12 months post vaccination.
Measured: on Day 1, Day 15, Day 29, Day 85, Day 180 and Month 12 post-vaccination
Percentage of Participants Seronegative at Baseline With Seroconversion as Compared to Baseline
Percentage of participants seronegative at baseline with Seroconversion (defined as >4-fold titer change compared to baseline) by Visit Pooled by Trial Arm
Measured: at Day 15, Day 29, Day 85, Day 180 and Month 12
Percentage of Participants Seropositive at Baseline With Seroconversion as Compared to Baseline
Percentage of participants seropositive at baseline with Seroconversion (defined as >4-fold titer change compared to baseline) by Visit Pooled by Trial Arm.
Measured: at Day 15, Day 29, Day 85, Day 180 and Month 12
Percentage of Participants With Seroconversion as Compared to Baseline Stratified by Age Stratum
Percentage of participants with Seroconversion (defined as >4-fold titer change compared to baseline) by Visit by Age Group and Trial Arm.
Measured: at Day 15, Day 29, Day 85, Day 180 and Month 12
Percentage of Participants With Seroconversion as Compared to Baseline by Dose
Percentage of participants with Seroconversion (defined as >4-fold titer change compared to baseline) by Visit Pooled by Trial Arm
Measured: at Day 15, Day 29, Day 85, Day 180 and Month 12
Percentage of Participants Seronegative at Baseline With a Seroresponse (Defined as PRNT50 ≥150 for Baseline Negative Participants) by Dose
Percentage of Participants with Seroresponse for CHIKV-Specific Neutralizing Antibody Titers (defined as PRNT50 ≥150) by Visit Pooled by Trial Arm.
Measured: on Day 15, Day 29, Day 85, Day 180 and Month 12 post-vaccination
Percentage of Participants With a Seroresponse Stratified by Age Stratum
Percentage of Participants with Seroresponse for CHIKV-Specific Neutralizing Antibody Titers (defined as PRNT50 ≥150) by Visit by Age Group and Trial Arm.
Measured: on Day 15, Day 29, Day 85, Day 180 and Month 12 post-vaccination
Percentage of Participants With a Seroresponse Stratified by Dose
Percentage of Participants with Seroresponse for CHIKV-Specific Neutralizing Antibody Titers (defined as PRNT50 ≥150) by Visit Pooled by Trial Arm.
Measured: on Day 15, Day 29, Day 85, Day 180 and Month 12 post-vaccination
Fold Change of CHIKV-specific Neutralizing Antibody Titers as Compared to Baseline in Participants Seronegative at Baseline
Fold Change for CHIKV-Specific Neutralizing Antibody Titers in seronegative Participants by Visit Pooled by Trial Arm.
Measured: at Days 15, 29, 85, 180 and at Month 12 post-vaccination
Fold Change of CHIKV-specific Neutralizing Antibody Titers as Compared to Baseline in Seropositive Participants
Fold Change for CHIKV-Specific Neutralizing Antibody Titers in seropositive Participants by Visit Pooled by Trial Arm.
Measured: at Days 15, 29, 85, 180 and at Month 12 post-vaccination
Fold Change of CHIKV-specific Neutralizing Antibody Titers as Compared to Baseline Stratified by Age Stratum
Fold Change for CHIKV-Specific Neutralizing Antibody Titers by Visit by Age Group and Trial Arm.
Measured: at Days 15, 29, 85, 180 and at Month 12 post-vaccination
Fold Change of CHIKV-specific Neutralizing Antibody Titers as Compared to Baseline Stratified by Dose
Fold Change for CHIKV-Specific Neutralizing Antibody Titers by Visit Pooled by Trial Arm.
Measured: at Days 15, 29, 85, 180 and at Month 12 post-vaccination
Percentage of Participants Seronegative at Baseline Reaching an at Least 4-fold, 8-fold, 16-fold or 64-fold Change in CHIKV-specific Neutralizing Antibody Titers Compared to Baseline
Percentage of Participants Reaching a 4-/8-/16-/64-Fold Change in Titers by Visit Pooled by Trial Arm.
Measured: at Day 15, Day 29, Day 85, Day 180 and Month 12
Percentage of Participants Reaching an at Least 4-fold, 8-fold, 16-fold or 64-fold Change in CHIKV-specific Neutralizing Antibody Titers Compared to Baseline Stratified by Age Stratum
Percentage of Participants Reaching a 4-/8-/16-/64-Fold Change in Titers by Visit by Age Group and Trial Arm.
Measured: at Day 15, Day 29, Day 85, Day 180 and Month 12
Percentage of Participants Reaching an at Least 4-fold, 8-fold, 16-fold or 64-fold Change in CHIKV-specific Neutralizing Antibody Titers Compared to Baseline by Dose
Percentage of Participants Reaching a 4-/8-/16-/64-Fold Change in Titers by Visit Pooled by Trial Arm.
Measured: at Day 15, Day 29, Day 85, Day 180 and Month 12
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted30 Oct 2023
- Study start18 Dec 2023
- Primary completion31 Jul 2024
- Study completion2 Jul 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Chikungunya Virus InfectionStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 304 participants (actual)
Sponsor and investigators
- Lead sponsor
- Valneva Austria GmbH
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Valneva Clinical Development, Study chair, Valneva Austria GmbH
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06106581
- Sponsor's protocol ID
- VLA1553-221
- Status last verified
- Aug 2025
- First submitted
- 24 Oct 2023
- Last updated
- 13 Aug 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: After trial completion, Valneva may provide access to individual de-identified participant data and related trial documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Trial Report (CTR)) upon request from qualified researchers, and subject to Valneva's review and approval.
Publications
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.
PubMed 41652122