Chikungunya Virus InfectionNCT07414524
VLA1553-403 Pregnancy Surveillance Study
An observational study of Chikungunya Virus Infection, run by Valneva Austria GmbH at 3 sites in Brazil.
Trial summary
This post-marketing, observational study evaluates pregnancy and infant outcomes up to 12 weeks after delivery among women who received the chikungunya vaccine (VLA1553) during pregnancy or within 30 days before their last menstrual period. Read more about this study
- Who is it for?
- Ages 18 years and older, women onlyHealthy volunteers can take part
- Conditions the study is for
- Chikungunya Virus Infection
- What is being tested?
- Live-attenuated CHIKV vaccine VLA1553 and Vaccine(s) approved for use during pregnancy by the MoH
- Type of treatment
- Vaccines
- How many people
- 200 participants
- Where
- 3 sitesBrazil
- Study dates
- 11 Jun 2026to 31 Dec 2027
- Phase
- Observational
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 years and older
- Women only
- Healthy volunteers accepted
- Adult, Older adult
Study population: The control group will consist of women who have received vaccine(s) approved for use during pregnancy by the MoH and who meet the matching criteria.
Who may be able to join
- VLA1553 vaccinated population:
- Women who have received the single dose of the VLA1553 vaccine during pregnancy or within the 30 days prior to the first day of the last menstrual period.
- Pregnant at the time of enrolment in the study.
- The participant understands and agrees to comply with the study procedures.
- Control group:
- Pregnant at the time of enrolment in the study.
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- Women who have received vaccine(s) approved for use during pregnancy by the MoH and who meet the matching criteria described in the protocol.
- The participant understands and agrees to comply with the study procedures.
- Women who have not received the VLA1553 vaccine during pregnancy or within the 30 days prior to the first day of the last menstrual period.
Who cannot join
- Women who do not provide informed consent.
- Women who are not part of the target population of the pilot vaccination strategy at the time 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: Observational Study to Evaluate the Safety of Live-attenuated Chikungunya Virus Vaccine (VLA1553) in Pregnant Women Exposed to the Vaccine in Brazil
This post-marketing, observational study evaluates pregnancy and infant outcomes up to 12 weeks after delivery among women who received the chikungunya vaccine (VLA1553) during pregnancy or within 30 days before their last menstrual period. A matched comparator cohort of pregnant women vaccinated with routine, pregnancy-recommended vaccines (not exposed to VLA1553) is included. No study procedures beyond routine care are performed.
Read the detailed description
This is an observational, non-interventional study in pregnant women who were vaccinated with the live-attenuated chikungunya virus vaccine (VLA1553) anytime during their pregnancy or within 30 days preceding their last menstrual period (VLA1553 group). The study protocol includes a comparator group of routinely vaccinated pregnant women not exposed to VLA1553 (control group).
The VLA1553 and control groups will be matched by gestational trimester and maternal age range (women <35 years of age at the time of enrolment and women >35 years of age) at exposure time. The study will collect information including vaccine exposure, demographic information, pregnancy data (e.g., date of positive pregnancy test, expected delivery date, previous pregnancy information), and medical history. Furthermore, data on pregnancy and infant outcomes up to 12 weeks post expected delivery date (EDD) will be compiled. The EDD will be calculated by counting 40 weeks from the first day of the LMP. This approach involves collecting data from the participating women onto the database by site staff and, if possible, confirmed and expanded by their PS-HCP as needed. Additionally, with consent, medical records may be accessed by study staff to further verify and supplement the information. This study will not provide or make recommendations on any vaccine use. Participation in the study is voluntary. Participation or lack of participation in this study will not change or influence a participant's standard of care.
- Conditions
- Chikungunya Virus Infection
- Being tested
- Live-attenuated CHIKV vaccine VLA1553, Vaccine(s) approved for use during pregnancy by the MoH
- 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 will start along with this observational study.
Vaccine(s) approved for use during pregnancy by the MoHBiological
Vaccine(s) approved for use during pregnancy by the MoH
| Study group | Role | What they receive |
|---|---|---|
| VLA1553 group | Women vaccinated with the chikungunya virus vaccine (VLA1553) anytime during their pregnancy or within 30 days preceding their last menstrual period. Receives: Biological: Live-attenuated CHIKV vaccine VLA1553 | |
| Control group | Women who have received vaccine(s) approved for use during pregnancy by the MoH and who meet the matching criteria. Receives: Biological: Vaccine(s) approved for use during pregnancy by the MoH |
What is being measured
The primary outcome is the main question the study is designed to answer.
Frequency (n,%) of individuals with any outcome (pregnancy and infant health), as described in the protocol.
Pregnancy and infant outcomes will be collected as follows:
- Pregnancy outcomes: stillbirths, pregnancy terminations (spontaneous and elective), preterm deliveries, neonatal deaths and term live births.
- Infant outcomes: births small for gestational age, major congenital malformations.
Measured: Study start through study completion, an average of 12 months
Frequency (n,%) of specific outcomes (pregnancy and infant health), as described in the protocol.
Pregnancy and infant outcomes will be collected as follows:
- Pregnancy outcomes: stillbirths, pregnancy terminations (spontaneous and elective), preterm deliveries, neonatal deaths and term live births.
- Infant outcomes: births small for gestational age, major congenital malformations.
Measured: Study start through study completion, an average of 12 months
Secondary outcomes (4)
Frequency (n,%) of individuals with any outcome (pregnancy and infant health), as described in the protocol in the VLA1553 group and the control group.
Pregnancy and infant outcomes will be collected as follows: 1. Pregnancy outcomes: stillbirths, pregnancy terminations (spontaneous and elective), preterm deliveries, neonatal deaths and term live births. 2. Infant outcomes: births small for gestational age, major congenital malformations.
Measured: Study start through study completion, an average of 12 months
Frequency (n,%) of specific outcomes (pregnancy and infant health), as described in the protocol in the VLA1553 group and the control group.
Pregnancy and infant outcomes will be collected as follows: 1. Pregnancy outcomes: stillbirths, pregnancy terminations (spontaneous and elective), preterm deliveries, neonatal deaths and term live births. 2. Infant outcomes: births small for gestational age, major congenital malformations.
Measured: Study start through study completion, an average of 12 months
Relative risk (RR) of any outcome (pregnancy and infant health) between pregnant women vaccinated with VLA1553 and pregnant women vaccinated with other vaccines recommended during pregnancy, as described in the protocol.
Pregnancy and infant outcomes will be collected as follows: 1. Pregnancy outcomes: stillbirths, pregnancy terminations (spontaneous and elective), preterm deliveries, neonatal deaths and term live births. 2. Infant outcomes: births small for gestational age, major congenital malformations.
Measured: Study start through study completion, an average of 12 months
Frequency (n,%) of individuals with SAEs (women and infants), following vaccination with VLA1553 or a control vaccine.
Pregnancy and infant outcomes will be collected as follows: 1. Pregnancy outcomes: stillbirths, pregnancy terminations (spontaneous and elective), preterm deliveries, neonatal deaths and term live births. 2. Infant outcomes: births small for gestational age, major congenital malformations.
Measured: Study start through study completion, an average of 12 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 Feb 2026
- Study start11 Jun 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
- Cohort
- Time perspective
- Prospective
- Enrolment
- 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
- NCT07414524
- Sponsor's protocol ID
- VLA1553-403
- Status last verified
- Jul 2026
- First submitted
- 9 Feb 2026
- Last updated
- 20 Jul 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided