VLA1553-403 Pregnancy Surveillance Study

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.

• Frequency (n,%) of individuals with any outcome (pregnancy and infant health), as described in the protocol in the VLA1553 group and the control group. [Срок оценки: 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. [Срок оценки: 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. [Срок оценки: 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. [Срок оценки: Study start through study completion, an average of 12 months]