Clinical Trial of the Adsorbed Acellular Pertussis (Tricomponent) DTaP-Haemophilus Influenzae Type b (Conjugate)-ACYW135 Group Meningococcal (Conjugate) Combined Vaccine

Inclusion Criteria: General Inclusion Criteria: * Participants aged 2 months (60-89 days), 3 months (90-119 days), 18-24 months, and 6 years of age, with legal guardians or authorized representatives willing to provide identification documentation; * Legal guardians or authorized representatives provide informed consent, voluntarily sign the informed consent form, and are able to comply with the requirements of the clinical trial protocol; Part I: Specific Inclusion Criteria: * Individuals aged 18-24 months who have completed a 3-dose DTaP-containing vaccine series and a meningococcal-containing vaccine primary series, but have not received a DTaP-containing booster dose; * Individuals aged 6 years who have completed 4 doses of DTaP-containing vaccine but have not received the 5th DTaP-containing vaccine dose; and have only completed the first meningococcal-containing vaccine booster dose, without receiving the second meningococcal-containing vaccine booster dose at age 6. Exclusion Criteria: General Exclusion Criteria for First Dose： * Infants born prematurely (delivery before 37 weeks gestation) or with low birth weight (\<2500g) at 2 months (60-89 days) or 3 months (90-119 days) of age; * Infants aged 2 months (60-89 days) or 3 months (90-119 days) with history of abnormal labor, asphyxia requiring resuscitation, or neurological impairment; * Severe congenital malformations or developmental disorders, genetic defects, or severe malnutrition; * History of severe adve…