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Observational Study to Assess the Effectiveness of VLA1553 Vaccine in Preventing Chikungunya During a Pilot Vaccination Strategy in Brazil

A Test-Negative Case-control Study to Evaluate the Effectiveness of VLA1553 Against Chikungunya Virus Disease During a Pilot Vaccination Strategy in Brazil

Status
Enrolling by invitation
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT07347002
Enrollment
1200
Registered
2026-01-16
Start date
2026-02-02
Completion date
2027-12-31
Last updated
2026-07-17

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Chikungunya Virus Infection

Brief 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.

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).

Interventions

Non-interventional study: VLA1553 is used in the pilot vaccination strategy which is linked to this observational study.

Sponsors

Valneva Austria GmbH
Lead SponsorINDUSTRY
Butantan Foundation
CollaboratorOTHER
Coalition for Epidemic Preparedness Innovations
CollaboratorOTHER

Study design

Observational model
CASE_CONTROL
Time perspective
RETROSPECTIVE

Eligibility

Sex/Gender
ALL
Age
18 Years to 59 Years
Healthy volunteers
Yes

Inclusion criteria

1. 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; 2. Are in an eligible age-group to receive the VLA1553 vaccine; 3. Have been notified in SINAN as a suspected case for CHIK or Dengue surveillance during the study period; 4. 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; 5. 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.

Exclusion criteria

1. Have inconclusive RT-PCR result for CHIKV; 2. Have a detectable vaccine virus identified via sequencing; 3. 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; 4. Have the first CHIKV-like symptom onset less than 14 days from date of vaccination.

Design outcomes

Primary

MeasureTime frame
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).Study start through study completion, an average of 23 months

Secondary

MeasureTime frame
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.Study start through study completion, an average of 23 months

Countries

Brazil

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Jul 18, 2026