Phase III Study of the Bivalent Enterovirus Inactivated Vaccine Vero Cell for Preventing Hand, Foot, and Mouth Disease in Children 6 to 71 Months Old

What this Trial Is About

Researchers are evaluating the efficacy, safety, and immune response of a bivalent enterovirus-inactivated vaccine Vero cell designed to prevent Hand, Foot, and Mouth Disease HFMD caused by CA16 infection in healthy children aged 6 to 71 months. This Phase III, multicenter, randomized, double-blind, controlled trial compares this investigational vaccine to an existing EV71-inactivated vaccine to see if it provides better or similar protection and immune response. Participants will be randomly assigned to receive either two doses of the bivalent enterovirus vaccine or two doses of the EV71 vaccine, given one month apart. The study includes a large group of 8000 children divided by age and vaccination history. After vaccination, children will be monitored through two epidemic seasons for signs of enterovirus infection, with swabs collected for lab testing when symptoms appear. Researchers will closely track any adverse events following vaccination, and subsets of participants will provide blood samples to assess detailed immune responses over time. During the study, guardians will report symptoms and adverse events, and researchers will collect throat or rectal swabs for lab confirmation if infection is suspected. Safety monitoring includes immediate and longer-term follow-up for side effects. Blood samples from selected participants will measure antibody levels at multiple time points up to 12 months after vaccination. The main outcomes include vaccine effectiveness against CA16-caused HFMD and immune responses to EV71. Participation involves regular visits, sample collections, and monitoring for up to two years post-vaccination.

Efficacy, Safety, and Immunogenicity of the Bivalent Inactivated Enterovirus Vaccine (Vero Cell)