Phase 2 Study to Evaluate Safety and Immune Response of Sinovac Quadrivalent Influenza Vaccine in Pregnant Women Aged 18 to 39

What this Trial Is About

Researchers are evaluating the immune response and safety of the Sinovac quadrivalent influenza vaccine QIV in healthy pregnant women aged 18 to 39 years who are between 20 and 32 weeks of pregnancy. This phase 2, randomized, double-blind, positive-controlled trial will compare Sinovac QIV with another influenza vaccine called Vaxigrip QIV to understand how well these vaccines work and their safety during pregnancy. Participants will be randomly assigned in a 21 ratio to receive a single 0.5 mL dose of either Sinovac QIV or Vaxigrip QIV. Blood samples will be collected before vaccination and 28 days after to measure immune responses. Additional blood samples from the mother at delivery and from the umbilical cord may be collected to assess antibody transfer to the baby. Safety will be monitored by recording immediate reactions within 30 minutes, local and systemic reactions within 7 days, and any other adverse events within 28 days after vaccination. Serious adverse events will be tracked up to 8 weeks after delivery. Throughout the study, participants will have scheduled visits for vaccination and blood draws. Researchers will review pregnancy and birth outcomes from medical records through hospital discharge. The main outcomes measured include rates of immune response against the flu virus 28 days after vaccination and the occurrence of adverse reactions. Safety monitoring extends through the postpartum period to ensure both mother and baby are observed for any issues related to vaccination.

Influenza Vaccine (Split Virion), Inactivated, Quadrivalent in Pregnant Women