Chikungunya Virus InfectionNCT07163845
Assessment of Chikungunya Virus Seroprevalence Before VLA1553 Vaccination in the Municipalities Selected for Participation in the VLA1553 Pilot Vaccination Strategy in Brazil
An observational study of Chikungunya Virus Infection, run by Valneva Austria GmbH at 4 sites in Brazil.
Trial summary
This is a cross-sectional serosurvey using household cluster sampling conducted before the VLA1553 pilot vaccination strategy will be implemented in about 10 municipalities in Brazil. Read more about this study
- Who is it for?
- Ages 2 years and olderHealthy 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
- 5,354 participants
- Where
- 4 sitesBrazil
- Study dates
- 22 Sep 2025to 31 Dec 2026
- 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 2 years and older
- All sexes
- Healthy volunteers accepted
- Child, Adult, Older adult
Study population: Study population will consist of individuals ≥2 years of age residing in the municipalities where the pilot VLA1553 vaccination strategy will take place and who meet the eligibility criteria
Who may be able to join
- Individuals residing in the selected municipalities of Brazil where the VLA1553 pilot vaccination strategy will be implemented.
- Individuals ≥2 years of age
- Individuals who sleep 3 nights a week or more in a household that is selected by cluster sampling.
Who cannot join
- 1. Individuals or their legally accepted representatives (LAR) who are not willing or not able to provide informed consent (and assent, as required) according to country-specific procedures.
Trial locations and contacts
4 sites in 1 country.
Brazil4 sites
Universidade Federal de Minas Gerais, CT Terapias Avançadas e Inovadoras
Belo Horizonte, Minas Gerais, 31270-901
Universidade Federal Do Ceará
Fortaleza, Ceará, 60430-160
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
This is a cross-sectional serosurvey using household cluster sampling conducted before the VLA1553 pilot vaccination strategy will be implemented in about 10 municipalities in Brazil.
Read the detailed description
Households will be selected randomly using a multi-stage random sampling at the census tract, street, and household levels, to select study participants. The study aims to prospectively evaluate the association between vaccination uptake and previous CHIKV exposure (pre-existing immunity to CHIKV infection) in the age-group approved per label in Brazil (e.g., adults [≥18 years of age] or individuals ≥12 years of age). Seroprevalence among vaccinated and unvaccinated individuals will be used to parameterize a probabilistic bias analysis conducted as part of the VE study. Finally, the study will explore the prevalence of CHIKV exposure in the different study communities before the VLA1553 pilot vaccination strategy in individuals ≥2 years of age.
- 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 carried out after this observational study.
What is being measured
The primary outcome is the main question the study is designed to answer.
To prospectively evaluate the association between vaccination uptake and previous CHIKV exposure (pre-existing immunity to CHIKV infection) after implementing a pilot vaccination in the age-group approved per label.
Measured: on Day 1
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted9 Sep 2025
- Study start22 Sep 2025
- Primary completion31 Jul 2026 (estimated)
- Study completion31 Dec 2026 (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
- Other
- Time perspective
- Cross-sectional
- Enrolment
- 5,354 participants (actual)
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
- NCT07163845
- Sponsor's protocol ID
- VLA1553-407
- Status last verified
- Feb 2026
- First submitted
- 1 Sep 2025
- Last updated
- 11 Feb 2026
- Results posted
- No
- Data monitoring committee
- Yes
- 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 11 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Assessment of Chikungunya Virus Seroprevalence Before VLA1553 Vaccination in the Municipalities Selected for Participation in the VLA1553 Pilot Vaccination Strategy in Brazil
- ClinicalTrials.gov ID
- NCT07163845
- Acronym / sponsor ID
- VLA1553-407
- Conditions
- Chikungunya Virus Infection
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 5,354 participants (actual)
- Lead sponsor
- Valneva Austria GmbHIndustry (pharma, biotech, devices)
- Collaborators
- Butantan Foundation, Coalition for Epidemic Preparedness Innovations
- Study start
- 22 Sep 2025 (actual)
- Primary completion
- 31 Jul 2026 (estimated)
- Study completion
- 31 Dec 2026 (estimated)
- First posted
- 9 Sep 2025 (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 a cross-sectional serosurvey using household cluster sampling conducted before the VLA1553 pilot vaccination strategy will be implemented in about 10 municipalities in Brazil.
Detailed description
Households will be selected randomly using a multi-stage random sampling at the census tract, street, and household levels, to select study participants. The study aims to prospectively evaluate the association between vaccination uptake and previous CHIKV exposure (pre-existing immunity to CHIKV infection) in the age-group approved per label in Brazil (e.g., adults [≥18 years of age] or individuals ≥12 years of age). Seroprevalence among vaccinated and unvaccinated individuals will be used to parameterize a probabilistic bias analysis conducted as part of the VE study. Finally, the study will explore the prevalence of CHIKV exposure in the different study communities before the VLA1553 pilot vaccination strategy in individuals ≥2 years of age.
Study design
- Observational model
- Other
- Time perspective
- Cross-sectional
Who may qualify
- Ages
- 2 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult, Older adult
- Study population
- Study population will consist of individuals ≥2 years of age residing in the municipalities where the pilot VLA1553 vaccination strategy will take place and who meet the eligibility criteria
Key inclusion criteria (3 listed)
- Individuals residing in the selected municipalities of Brazil where the VLA1553 pilot vaccination strategy will be implemented.
- Individuals ≥2 years of age
- Individuals who sleep 3 nights a week or more in a household that is selected by cluster sampling.
Key exclusion criteria (1 listed)
- 1. Individuals or their legally accepted representatives (LAR) who are not willing or not able to provide informed consent (and assent, as required) according to country-specific procedures.
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 carried out after this observational study. | Biological | – |
Primary outcome
To prospectively evaluate the association between vaccination uptake and previous CHIKV exposure (pre-existing immunity to CHIKV infection) after implementing a pilot vaccination in the age-group approved per label.
Time frame: on Day 1
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 11 Feb 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. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
4 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 4 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 3 inclusion and 1 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: under way, not looking for participants, as of the sponsor's last update on 11 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 4 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?
To prospectively evaluate the association between vaccination uptake and previous CHIKV exposure (pre-existing immunity to CHIKV infection) after implementing a pilot vaccination in the age-group approved per label. (time frame: on Day 1). 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 11 Feb 2026.