An observational study in Chikungunya Virus Infection, sponsored by Valneva Austria GmbH. Enrolling by invitation at 3 sites in Brazil. Open to participants aged 18 Years to 59 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-07-17.
Sponsored by Valneva Austria GmbH (part of Valneva) · Observational
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.
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).
88 studies on the registry are indexed under Chikungunya Fever; 21 are open to participants now.
This study's planned enrollment of 1,200 is above the median of 600 across 26 observational studies indexed under Chikungunya Fever.
Browse Chikungunya Fever studies →Valneva Austria GmbH is the lead sponsor of 44 studies on the registry; 2 are open to participants now.
Of its 7 completed or terminated interventional studies of FDA-regulated products, 4 (57%) have results posted.
First submitted after Valneva Austria GmbH became part of Valneva.
Counted across the registry records on this site, refreshed daily.
Residents of the selected areas, within the age limits approved for the PVS, presenting at the health care facilities during the study period.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Biological: Live-attenuated CHIKV vaccine VLA1553
Biological: Live-attenuated CHIKV vaccine VLA1553
Non-interventional study: VLA1553 is used in the pilot vaccination strategy which is linked to this observational study.
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
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
Detection of CHIKV in VLA1553-vaccinated (≥14 days after vaccination) and unvaccinated individuals with CHIKV-like symptoms confirmed by RT-PCR, stratified by sex and age group (≥18 to 59 and ≥ 60 years, depending on the age group approved for the PVS)
Time frame: Study start through study completion, an average of 23 months
Detection of CHIKV in VLA1553-vaccinated (≥14 days after vaccination) and unvaccinated study individuals with CHIKV-like symptoms confirmed by RT-PCR, stratified by time since vaccination (from 0 to 6 months after Day 15)
Time frame: Study start through study completion, an average of 23 months
CHIKV hospitalizations (confirmed by RT-PCR) in VLA1553-vaccinated (≥14 days after vaccination) and unvaccinated study individuals; CHIKV deaths (confirmed by RT-PCR) in VLA1553-vaccinated (≥14 days after vaccination) and unvaccinated study individuals
Time frame: Study start through study completion, an average of 23 months
Magnitude and direction of estimated level of bias due to unmeasured pre-vaccination strategy CHIKV infection, and estimated VE corrected for this bias.
Time frame: Study start through study completion, an average of 23 months
Plan to share: Undecided
No publications or documents are linked to this record.
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