Meningococcal Meningitis

This trial adopts an open-label design combined with randomized, blinded, placebo-controlled and active-controlled design. The purpose of this trial is to evaluate the safety and immunogenicity of a Group ACYW135X Meningococcal Conjugate Vaccine. This study is planned to enroll 150 participants in total, with healthy individuals aged 2 to 59 years as participants. Among them, participants aged 18 to 59 years and 7 to 17 years will be assigned to the open-label design arm, while participants aged 4 to 6 years will be assigned to the randomized, blinded, placebo-controlled design arms.