An observational study in Chikungunya Virus Infection, sponsored by Valneva Austria GmbH. Enrolling by invitation at 3 sites in Brazil. Open to female participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-07-20.
Sponsored by Valneva Austria GmbH (part of Valneva) · Observational
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.
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.
88 studies on the registry are indexed under Chikungunya Fever; 21 are open to participants now.
This study's planned enrollment of 200 is below 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.
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.
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.
VLA1553 vaccinated population:
Control group:
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Women vaccinated with the chikungunya virus vaccine (VLA1553) anytime during their pregnancy or within 30 days preceding their last menstrual period.
Biological: Live-attenuated CHIKV vaccine VLA1553
Women who have received vaccine(s) approved for use during pregnancy by the MoH and who meet the matching criteria.
Biological: Vaccine(s) approved for use during pregnancy by the MoH
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 MoH
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: 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.
Time frame: 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: 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.
Time frame: Study start through study completion, an average of 12 months
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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: Study start through study completion, an average of 12 months
Plan to share: Undecided
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