Chikungunya Virus InfectionNCT07347002
Observational Study to Assess the Effectiveness of VLA1553 Vaccine in Preventing Chikungunya During a Pilot Vaccination Strategy in Brazil
An observational study of Chikungunya Virus Infection, run by Valneva Austria GmbH at 3 sites in Brazil.
Trial summary
This is an observational, non-interventional, test-negative case-control (TNCC) study to estimate the vaccine effectiveness of VLA1553 against Chikungunya virus in a real-world setting. Read more about this study
- Who is it for?
- Ages 18 to 59 yearsHealthy volunteers can take part
- Conditions the study is for
- Chikungunya Virus Infection
- What is being tested?
- Live-attenuated CHIKV vaccine VLA1553
- Type of treatment
- Vaccines
- How many people
- 1,200 participants
- Where
- 3 sitesBrazil
- Study dates
- 2 Feb 2026to 31 Dec 2027
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
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 18 to 59 years
- All sexes
- Healthy volunteers accepted
- Adult
Study population: Residents of the selected areas, within the age limits approved for the PVS, presenting at the health care facilities during the study period.
Who may be able to join
- Have a CHIKV RT-PCR result registered from a municipality where the pilot vaccination strategy is implemented and is in scope of the VLA1553-402 study;
- Are in an eligible age-group to receive the VLA1553 vaccine;
- Have been notified in SINAN as a suspected case for CHIK or Dengue surveillance during the study period;
- Have a sample registered in GAL that is collected within 0-5 days following the onset of CHIKV-like symptoms and is tested for CHIKV using RT-PCR;
- Have complete data in the Brazilian MoH databases (SINAN and GAL) on age, sex, municipality of residence, sample collection date, and date of symptom onset and the healthcare facilities where the suspected case was reported.
Who cannot join
- Have inconclusive RT-PCR result for CHIKV;
- Have a detectable vaccine virus identified via sequencing;
- For vaccinated and CHIV RT-PCR positive individuals, have no valid sequencing result available for RT-PCR positive samples collected within 30 days post-vaccination;
- Have the first CHIKV-like symptom onset less than 14 days from date of vaccination.
Trial locations and contacts
3 sites in 1 country. Contact the study team or a site near you to ask about taking part.
Brazil3 sites
Universidade Federal de Minas Gerais, CT Terapias Avançadas e Inovadoras
Belo Horizonte, Minas Gerais, 31270-901
Centro de Pesquisas Clínicas Universidade Federal Sergipe, Hospital e Maternidade São João de Deus
Laranjeiras, Sergipe, 49060-025
Fundação Faculdade Regional De Medicina De São José Do Rio Preto
São Pedro, São Paulo, 15090-000
About this study
Official title: A Test-Negative Case-control Study to Evaluate the Effectiveness of VLA1553 Against Chikungunya Virus Disease During a Pilot Vaccination Strategy in Brazil
This is an observational, non-interventional, test-negative case-control (TNCC) study to estimate the vaccine effectiveness of VLA1553 against Chikungunya virus in a real-world setting.
Read the detailed description
The objective of this study is to evaluate the effectiveness of vaccination with VLA1553 in the prevention of laboratory-confirmed symptomatic cases of CHIK after a single dose of VLA1553 administered as part of a pilot vaccination strategy following licensure in Brazil.
The study will commence following the implementation of the pilot vaccination strategy in selected municipalities. Data for the analyses will be obtained from official Brazilian Ministry of Health surveillance systems, specifically the GAL (Laboratory Environment Management System), SINAN (Notifiable Diseases Information System), and Si-PNI (National Immunization Program Information System).
- Conditions
- Chikungunya Virus Infection
- Being tested
- Live-attenuated CHIKV vaccine VLA1553
- Medical subject headings
- Chikungunya Fever
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Live-attenuated CHIKV vaccine VLA1553Biological
Non-interventional study: VLA1553 is used in the pilot vaccination strategy which is linked to this observational study.
| Study group | Role | What they receive |
|---|---|---|
| Cases: Test-positive for Chikungunya virus | Not described Receives: Biological: Live-attenuated CHIKV vaccine VLA1553 | |
| Controls: Test-negative for Chikungunya virus | Not described Receives: Biological: Live-attenuated CHIKV vaccine VLA1553 |
What is being measured
The primary outcome is the main question the study is designed to answer.
Detection of CHIKV in VLA1553-vaccinated (≥14 days after vaccination) and unvaccinated study individuals with CHIKV-like symptoms confirmed by reverse transcriptase polymerase chain reaction (RT-PCR).
Measured: Study start through study completion, an average of 23 months
Secondary outcomes (1)
Detection of CHIKV in VLA1553-vaccinated (≥14 days after vaccination) and unvaccinated study individuals ≥50 years of age with CHIKV-like symptoms confirmed by RT-PCR.
Measured: Study start through study completion, an average of 23 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Jan 2026
- Study start2 Feb 2026
- Primary completion31 Dec 2027 (estimated)
- Study completion31 Dec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- 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
- Observational
- Observational model
- Case-control
- Time perspective
- Retrospective
- Enrolment
- 1,200 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Valneva Austria GmbH
- Sponsor type
- Industry (pharma, biotech, devices)
- Collaborators
- Butantan Foundation, Coalition for Epidemic Preparedness Innovations
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07347002
- Sponsor's protocol ID
- VLA1553-402
- Status last verified
- Jul 2026
- First submitted
- 4 Dec 2025
- Last updated
- 17 Jul 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 17 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Test-Negative Case-control Study to Evaluate the Effectiveness of VLA1553 Against Chikungunya Virus Disease During a Pilot Vaccination Strategy in Brazil
- ClinicalTrials.gov ID
- NCT07347002
- Acronym / sponsor ID
- VLA1553-402
- Conditions
- Chikungunya Virus Infection
- Study type
- Observational
- Recruitment status
- Enrolling by invitation
- Enrolment
- 1,200 participants (estimated)
- Lead sponsor
- Valneva Austria GmbHIndustry (pharma, biotech, devices)
- Collaborators
- Butantan Foundation, Coalition for Epidemic Preparedness Innovations
- Study start
- 2 Feb 2026 (actual)
- Primary completion
- 31 Dec 2027 (estimated)
- Study completion
- 31 Dec 2027 (estimated)
- First posted
- 16 Jan 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This is an observational, non-interventional, test-negative case-control (TNCC) study to estimate the vaccine effectiveness of VLA1553 against Chikungunya virus in a real-world setting.
Detailed description
The objective of this study is to evaluate the effectiveness of vaccination with VLA1553 in the prevention of laboratory-confirmed symptomatic cases of CHIK after a single dose of VLA1553 administered as part of a pilot vaccination strategy following licensure in Brazil.
The study will commence following the implementation of the pilot vaccination strategy in selected municipalities. Data for the analyses will be obtained from official Brazilian Ministry of Health surveillance systems, specifically the GAL (Laboratory Environment Management System), SINAN (Notifiable Diseases Information System), and Si-PNI (National Immunization Program Information System).
Study design
- Observational model
- Case-control
- Time perspective
- Retrospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Cases: Test-positive for Chikungunya virus | – | Biological: Live-attenuated CHIKV vaccine VLA1553 |
| Controls: Test-negative for Chikungunya virus | – | Biological: Live-attenuated CHIKV vaccine VLA1553 |
Who may qualify
- Ages
- 18 to 59 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
- Study population
- Residents of the selected areas, within the age limits approved for the PVS, presenting at the health care facilities during the study period.
Key inclusion criteria (5 listed)
- Have a CHIKV RT-PCR result registered from a municipality where the pilot vaccination strategy is implemented and is in scope of the VLA1553-402 study;
- Are in an eligible age-group to receive the VLA1553 vaccine;
- Have been notified in SINAN as a suspected case for CHIK or Dengue surveillance during the study period;
- Have a sample registered in GAL that is collected within 0-5 days following the onset of CHIKV-like symptoms and is tested for CHIKV using RT-PCR;
- Have complete data in the Brazilian MoH databases (SINAN and GAL) on age, sex, municipality of residence, sample collection date, and date of symptom onset and the healthcare facilities where the suspected case was reported.
Key exclusion criteria (4 listed)
- Have inconclusive RT-PCR result for CHIKV;
- Have a detectable vaccine virus identified via sequencing;
- For vaccinated and CHIV RT-PCR positive individuals, have no valid sequencing result available for RT-PCR positive samples collected within 30 days post-vaccination;
- Have the first CHIKV-like symptom onset less than 14 days from date of vaccination.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Live-attenuated CHIKV vaccine VLA1553Non-interventional study: VLA1553 is used in the pilot vaccination strategy which is linked to this observational study. | Biological | Cases: Test-positive for Chikungunya virus, Controls: Test-negative for Chikungunya virus |
Primary outcome
Detection of CHIKV in VLA1553-vaccinated (≥14 days after vaccination) and unvaccinated study individuals with CHIKV-like symptoms confirmed by reverse transcriptase polymerase chain reaction (RT-PCR).
Time frame: Study start through study completion, an average of 23 months
1 secondary outcome
Detection of CHIKV in VLA1553-vaccinated (≥14 days after vaccination) and unvaccinated study individuals ≥50 years of age with CHIKV-like symptoms confirmed by RT-PCR.
Time frame: Study start through study completion, an average of 23 months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 17 Jul 2026.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
The record lists no contact. Use the official record to reach the sponsor.
3 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Chikungunya Virus Infection, run by Valneva Austria GmbH at 3 sites in Brazil.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: enrolling by invitation, as of the sponsor's last update on 17 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 3 sites in Brazil. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Detection of CHIKV in VLA1553-vaccinated (≥14 days after vaccination) and unvaccinated study individuals with CHIKV-like symptoms confirmed by reverse transcriptase polymerase chain reaction (RT-PCR). (time frame: Study start through study completion, an average of 23 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 17 Jul 2026.