Pivotal Study to Evaluate Safety and Immunogenicity of a Live-Attenuated Chikungunya Virus Vaccine Candidate in Adults
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ClinicalTrials.gov Identifier: NCT04546724 |
Recruitment Status :
Completed
First Posted : September 14, 2020
Last Update Posted : December 22, 2021
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Condition or disease | Intervention/treatment | Phase |
---|---|---|
Chikungunya Virus Infection | Biological: VLA1553 Biological: Placebo | Phase 3 |
This is a prospective, double-blinded, multicenter, randomized, pivotal Phase 3 study comprising approximately 4,060 subjects aged 18 years or above randomized in a 3:1 ratio to the live-attenuated CHIKV vaccine candidate (VLA1553) or placebo. The final dose of lyophilized VLA1553 or placebo will be administered as a single intramuscular immunization. Subjects in this study will be stratified into two age strata of 18 to 64 years and 65 years of age or above. The primary objective of the study is to evaluate the immunogenicity and safety of the final dose of VLA1553 28 days following the single immunization. Immunogenicity evaluations in the immunogenicity subset will include the proportion of subjects with seroprotective neutralizing CHIKV antibody titers above a surrogate threshold indicative of protection. The surrogate of protection reasonably likely to predict clinical benefit has been established in non-human primate passive transfer studies using human sera from the Phase 1 study. Safety data collection and immunogenicity will continue to be assessed until Month 6
The first enrolled and randomized approximately 500 subjects will comprise the immunogenicity subset.
Study Type : | Interventional (Clinical Trial) |
Actual Enrollment : | 4131 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Masking: | Double (Participant, Investigator) |
Primary Purpose: | Prevention |
Official Title: | A Multicenter, Randomized, Placebo-Controlled, Double-Blinded Pivotal Study To Evaluate Safety And Immunogenicity Of A Live-Attenuated Chikungunya Virus Vaccine Candidate In Adults Aged 18 Years And Above |
Actual Study Start Date : | September 17, 2020 |
Actual Primary Completion Date : | May 19, 2021 |
Actual Study Completion Date : | October 14, 2021 |

Arm | Intervention/treatment |
---|---|
Active Comparator: VLA1553 |
Biological: VLA1553
Single intramuscular vaccination on Day 1 with VLA1553, a lyophilized live-attenuated Chikungunya vaccine candidate; 1x10E4 TCID50 per dose |
Placebo Comparator: Placebo |
Biological: Placebo
Single intramuscular vaccination on Day 1 with Phosphate-Buffered Saline (PBS) as placebo |
- Proportion of subjects with a seroprotective CHIKV antibody level determined by µPRNT (Micro Plaque Reduction Neutralization Test) for baseline negative subjects 28 days post-vaccination. [ Time Frame: up to Day 29 after single vaccination ]
- Immune response as measured by CHIKV-specific neutralizing antibody titers on Day 8, Day 29, Day 85 and Month 6 post-vaccination as determined by µPRNT assay [ Time Frame: until Day 8, 85 and Month 6 ]
- Proportion of subjects with seroprotective CHIKV antibody levels as determined by µPRNT for baseline negative subjects [ Time Frame: until Day 8, 29, 85 and Month 6 ]
- Proportion of subjects with seroconversion at Day 29 and Month 6 as determined by µPRNT assay [ Time Frame: until Day 29 and Month 6 ]
- Fold increase of CHIKV-specific neutralizing antibody titers determined by µPRNT assay at Days 8, 29, 85 and Month 6 post-vaccination as compared to baseline [ Time Frame: until Day 8, 29, 85 and Month 6 ]
- Frequency and severity of unsolicited Adverse Events within 28 days post-vaccination [ Time Frame: until Day 29 ]
- Frequency and severity of solicited injection site and systemic reactions [ Time Frame: as recorded in the subject diaries ]
- Frequency and severity of any Adverse Event during the entire study period [ Time Frame: until Month 6 ]
- Frequency and severity of any Serious Adverse Event (SAE) during the entire study period [ Time Frame: until Month 6 ]
- Frequency and severity of any Adverse Event of Special Interest (AESI) [ Time Frame: until Month 6 ]

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.
Ages Eligible for Study: | 18 Years and older (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | Yes |
Inclusion Criteria:
- 18 years of age or above on the Day of screening
- able to provide informed consent
- generally healthy as determined by the Investigator's clinical judgement based on medical history, physical examination and screening laboratory tests
-
for women of childbearing potential:
- practiced an adequate method of contraception during 30 days before screening
- negative serum or urine pregnancy test at screening
- agrees to employ adequate birth control measures for the first three months post-vaccination (i.e. until Day 85).
Main Exclusion Criteria:
- CHIKV infection in the past, including suspected CHIKV infection; is taking medication or other treatment for unresolved symptoms attributed to a previous CHIKV infection; or has participated in a clinical study involving an investigational CHIKV vaccine
- acute or recent infection
- live virus vaccine within 28 days or inactivated vaccine within 14 days prior to vaccination in this study or plans to receive a vaccine within 28 days or 14 days after vaccination, respectively
- abnormal findings in any required study investigations (including medical history, physical examination, and clinical laboratory) considered clinically relevant by the Investigator which pose a risk for participation in the study
- medical history of or currently has acute or progressive, unstable or uncontrolled clinical conditions that pose a risk for participation in the study
- history of immune-mediated or clinically relevant arthritis / arthralgia
- history of malignancy in the past 5 years other than squamous cell or basal cell skin cancer. If there has been surgical excision or treatment more than 5 years ago that is considered to have achieved a cure, the subject may be enrolled.
- known or suspected defect of the immune system, such as subjects with congenital or acquired immunodeficiency, including infection with HIV, status post organ transplantation or immuno-suppressive therapy within 4 weeks prior to vaccination.
- history of any vaccine related contraindicating event (e.g., anaphylaxis, allergy to components of the candidate vaccine, other known contraindications)
- with clinical conditions representing a contraindication to intramuscular vaccination and blood draws
- pregnant or lactating at the time of enrollment
- Donation of blood, blood fractions or plasma within 30 days or received blood-derived products (e.g. plasma) within 90 days prior to vaccination in this study or plans to donate blood or use blood products until Day 180 of the study
- rash, dermatological condition or tattoos that would, in the opinion of the Investigator, interfere with injection site reaction rating
- known or suspected problem with alcohol or drug abuse as determined by the Investigator
- any condition that, in the opinion of the Investigator, may compromise the subjects well-being, might interfere with evaluation of study endpoints, or would limit the subject's ability to complete the study;
- committed to an institution (by virtue of an order issued either by the judicial or the administrative authorities)
- Participation in another clinical study involving an investigational medicinal product (IMP) or device within 30 days prior to study enrollment or is scheduled to participate in another clinical study involving an IMP, or device during the course of this study
- member of the team conducting the study or in a dependent relationship with one of the study team members. Dependent relationships include close relatives (i.e., children, partner/spouse, siblings, parents) as well as employees of the Investigator or site personnel conducting the study.

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT04546724

Study Chair: | Valneva Clinical Development | Valneva Austria GmbH |
Responsible Party: | Valneva Austria GmbH |
ClinicalTrials.gov Identifier: | NCT04546724 |
Other Study ID Numbers: |
VLA1553-301 |
First Posted: | September 14, 2020 Key Record Dates |
Last Update Posted: | December 22, 2021 |
Last Verified: | December 2021 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | Undecided |
Studies a U.S. FDA-regulated Drug Product: | Yes |
Studies a U.S. FDA-regulated Device Product: | No |
VLA1553 Chikungunya Virus Infection CHIKV Live-attenuated Chikungunya virus vaccine |
Virus Diseases Chikungunya Fever Infections Alphavirus Infections |
Arbovirus Infections Vector Borne Diseases Togaviridae Infections RNA Virus Infections |