NCT07414524

VLA1553-403 Pregnancy Surveillance Study

Observational Study to Evaluate the Safety of Live-attenuated Chikungunya Virus Vaccine (VLA1553) in Pregnant Women Exposed to the Vaccine in Brazil

• Status: Not Yet Recruiting
• Phase: —
• Study type: Observational
• Enrollment: 200 (estimated)
• Sponsor: Valneva Austria GmbH · Industry
• Sex: Female
• Age: 18 Years
• Healthy volunteers: Accepted

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. 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.

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

Interventions

Type	Name	Description
BIOLOGICAL	Live-attenuated CHIKV vaccine VLA1553	Non-interventional study: VLA1553 is used in the pilot vaccination strategy which will start along with this observational study.
BIOLOGICAL	Vaccine(s) approved for use during pregnancy by the MoH	Vaccine(s) approved for use during pregnancy by the MoH

Timeline

• Start date: 2026-03-31
• Primary completion: 2027-12-31
• Completion: 2027-12-31
• First posted: 2026-02-17
• Last updated: 2026-02-17