This study was divided into two stages. The first stage study was an early safety assessment study among 80 subjects. The first stage study was conducted gradually in 20 subjects aged 18-50 years, 20 subjects aged 7-17 years, and 40 subjects aged 2-6 years. The second phase was a randomized, double-blind, controlled, non-inferiority phase III clinical trial in 1200 healthy infants aged 2-6 years, to evaluate the immunogenicity and safety of the experimantal vaccine after immunization.
This study is a randomized, double-blinded, and controlled phase III clinical trial of the Group A and C meningococcal polysaccharide vaccine to evaluate the safety and immunogenicity of the vaccine in healthy infants aged 2-6 years.