A single-center and open-labeled Phase I study, designed to evaluate the safety by observing the occurrence of adverse events and change of hematology, liver and renal function after vaccination of a meningococcal group A, C, Y, and W135 conjugate vaccine in healthy population aged 2 months to 55 years old.

Inclusion Criteria:

• Healthy children, adolescents and adults (age range: 2 months to 55 years old) based on medical history, physical examination or judgement of the investigator
• Subjects aged ≥18 years old voluntarily agree to participate in this clinical study and sign the informed consent form; or for subjects aged <18 years old, the legal guardian voluntarily agrees that his/her child to participate in this clinical study, and sign the informed consent form. For juveniles aged ≥8 years old, both the subject and his/her legal guardians should voluntarily agree to participate in this clinical study and sign the informed consent form.
• The subject and his/her legal guardians as well as the family members are able to follow the request of clinical study protocol.
• Subjects aged 2 or 3 months should have no vaccination history of any meningococcal vaccine; subjects aged 7~23 months should have not received any other meningococcal vaccine except the meningococcal group A polysaccharide vaccine included in National Immunization Program, and the time since last vaccination of meningococcal group A polysaccharide vaccine should be >6 months; for subjects ≥2 years, the time since last vaccination of meningococcal vaccine should be >2 years.
• For subjects aged ≥2 years, there should be no clinically significant abnormal hematology, liver and renal function results judged by the investigator before immunization.
• Subjects should not receive any attenuated live vaccine 14 days, or inactivated vaccine 7 days before or after vaccination.
• Axillary temperature ≤37.0℃.

Exclusion Criteria for First Dose:

• Subjects aged 2 or 3 months at enrollment with birth weight <2.5 kg.
• Subjects aged 2 or 3 months at enrollment had received blood products and immunoglobin after birth; subjects of other age groups had received blood products or immunoglobin in <3 months before vaccination.
• Subjects aged <12 months at enrollment are diagnosed as with pathological jaundice or have a history of pathological jaundice.
• Subjects aged <2 months at enrollment had abnormal labor (dystocia, assisted instrumental delivery) or with the history of asphyxia or nervous damage.
• Subjects aged ≥18 years who are planning pregnancy, or are pregnant, or are breastfeeding.
• Subjects aged ≥18 years with uncontrollable hypertension (during screening: systolic BP >140 mmHg or diastolic BP >90 mmHg).
• Subjects are known to be allergic to certain components contained in the investigational vaccine (mainly include: capsular polysaccharide of meningococcal group A, group C, group Y, or group W135, diphtheria toxoid or diphtheria antigen).
• Subjects with the history of serious allergy to any vaccine or drug. (including but not limited to: allergic shock, allergic laryngeal edema, allergic purpura, thrombocytopenic purpura, local allergic necrosis reaction [Arthus reaction]).
• Subjects with the history of meningitis.
• Subjects with moderate to severe fever (axillary temperature ≥38.0℃) in last 3 days.
• Subjects with the history or family history of convulsion, seizure, encephalopathy, or psychiatric disorders.
• Subjects with definite diagnosis of thrombocytopenia or other coagulation disorders.
• Subjects with primary or secondary immunological dysfunction, including HIV infection, disorder or resection of thyroid, pancreas, liver, spleen or kidney; or needed treatment due to thyroid disorders in last 12 months (time interval <12 months).
• Subjects have received immunosuppressive therapy, cytotoxic therapy, corticosteroid hormone (not include corticosteroid hormone spray for allergic rhinitis, epithelial corticosteroid hormone for acute and non-complicated dermatitis) in last 6 months (time interval <6 months).
• Subjects with known congenital malformation, developmental disabilities or clinically confirmed serious chronic diseases (e.g., Down syndrome, diabetes mellitus, sickle cell anemia or nervous disease, Guillain-Barre syndrome, etc.).
• Subjects with known or suspected diseases that are likely to affect the vaccination by investigators' judgement, such as: serious respiratory diseases, acute infection or the active period of chronic disease, serious cardiovascular diseases, liver and renal diseases, malignant tumors, serious infectious or allergic skin diseases.
• Subjects are participating or plan to participate in other clinical trials of investigational medications.
• Any other conditions that may influence the evaluation of clinical study by investigators' judgement.

Exclusion Criteria for Second and Third Dose:

• New conditions that conforms with the exclusion criteria for first dose.
• Subjects that develop grade 4 adverse reactions after vaccination of investigational vaccine.
• Subjects that develop serious allergic reactions after vaccination of investigational vaccine.
• Any other conditions that may influence the evaluation of clinical study by investigators' judgement based on the exclusion criteria for first dose.