A Phase III Clinical Trial of the Group A Meningococcal Polysaccharide Vaccine
A Phase III Clinical Trial of the Group A Meningococcal Polysaccharide Vaccine
This study is a randomized, double-blinded, and controlled phase III clinical trial of the
 Group A meningococcal polysaccharide vaccine to evaluate the safety and immunogenicity of the
 vaccine in healthy infants aged 6-15 months.
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 3-17 years, and 40 subjects aged 6-15 months. The second phase
 was a randomized, double-blind, controlled, non-inferiority phase III clinical trial in 1200
 healthy infants aged 6-15 months, to evaluate the immunogenicity and safety of the
 experimental vaccine after two doses of immunization.
-  The First stage study (An early safety assessment study):

 -  18-50 years group:

 -  Inclusion Criteria

 1. Healthy adults aged 18 to 50 years.

 2. Proven legal identity.

 3. Participants should understand the contents of the informed consent form,
 the vaccine in this trial, voluntarily sign the informed consent form, and
 be capable of using thermometers, scales, and filling in diary cards and
 contact cards as required.

 4. Participants should be able to communicate well with investigators,
 understand and comply with the requirements of this trial.

 5. Axillary temperature ≤37.0℃.

 -  Exclusion Criteria:

 1. Contraindications for vaccination.

 2. History of allergy to vaccines or drugs.

 3. History of Epidemic Cerebrospinal Meningitis.

 4. Immunization with any Group A meningococcal conjugate vaccine or
 polysaccharide vaccine within 12 months.

 5. Immunization with any Group A and C meningococcal conjugate vaccine or
 polysaccharide vaccine within 3 years.

 6. Immunization with any vaccine within 30 days.

 7. Participants with convulsion, epilepsy, encephalopathy and psychiatric
 history or family history of epilepsy.

 8. History of abnormal clinical manifestations and serious diseases to be
 excluded, including but not limited to nervous system, cardiovascular
 system, blood and lymphatic system, immune system, kidney, liver,
 gastrointestinal tract, respiratory system, metabolism, bones and other
 system diseases, and a history of malignant tumors.

 9. Those who developed acute disease or acute attack of chronic disease.

 10. Surgical removal of spleen or other important organs for any reason.

 11. History of thrombocytopenia or other coagulation disorders may cause
 contraindication of subcutaneous injection.

 12. Blood products such as immunoglobulin were received within 30 days before
 vaccination.

 13. Have received immunosuppressive therapy or other immunomodulatory drugs
 within 6 months before signing the informed consent form (Note: inhaled or
 topical hormone drugs, except those with an interval of 14 days or more from
 the date of signing the informed consent form).

 14. Those who participated in other clinical studies.

 15. Participants who have a positive pregnancy test, or are breastfeeding, or
 plan to become pregnant, or plan to donate sperm or eggs from the screening
 to 12 months after the second vaccination.

 16. Any other situations judged by investigators as not suitable for
 participating in this study.

 -  3-17 years group:

 -  Inclusion Criteria

 1. Healthy volunteer aged 3 to 17 years.

 2. Proven legal identity.

 3. Participants and their legal guardians should understand the contents of the
 informed consent form, the vaccine in this trial, voluntarily sign the
 informed consent form, and be capable of using thermometers, scales, and
 filling in diary cards and contact cards as required.

 4. Participants and their legal guardians should be able to communicate well
 with investigators, understand and comply with the requirements of this
 trial.

 5. Axillary temperature ≤37.0℃.

 -  Exclusion Criteria:

 1. Contraindications for vaccination.

 2. History of allergy to vaccines or drugs.

 3. History of Epidemic Cerebrospinal Meningitis.

 4. Immunization with any Group A meningococcal conjugate vaccine or
 polysaccharide vaccine within 12 months.

 5. Immunization with any Group A and C meningococcal conjugate vaccine or
 polysaccharide vaccine within 3 years.

 6. Immunization with any vaccine within 30 days.

 7. Participants with convulsion, epilepsy, encephalopathy and psychiatric
 history or family history of epilepsy.

 8. Participant who has congenital heart disease, congenital malformation,
 Down's syndrome, sickle cell anemia or severe diseases with previous
 clinical manifestations that need to be excluded, including but not limited
 to nervous system, genetic defect disease (such as faba bean disease),
 cardiovascular system, blood and lymphatic system, immune system, kidney,
 liver, gastrointestinal tract, respiratory system, metabolism and bone
 system diseases, and History of malignant tumor.

 9. Those who developed acute disease or acute attack of chronic disease.

 10. Surgical removal of spleen or other important organs for any reason.

 11. History of thrombocytopenia or other coagulation disorders may cause
 contraindication of subcutaneous injection.

 12. Blood products such as immunoglobulin were received within 30 days before
 vaccination.

 13. Have received immunosuppressive therapy or other immunomodulatory drugs
 within 6 months before signing the informed consent form (Note: inhaled or
 topical hormone drugs, except those with an interval of 14 days or more from
 the date of signing the informed consent form).

 14. Those who participated in other clinical studies.

 15. Women with positive pregnancy test after menarche.

 16. Any other situations judged by investigators as not suitable for
 participating in this study.

 -  6-15 months group:

 -  Inclusion Criteria

 1. Healthy infants aged 6 to 15 months.

 2. Proven legal identity.

 3. Participants' legal guardians should understand the contents of the informed
 consent form, the vaccine in this trial, voluntarily sign the informed
 consent form, and be capable of using thermometers, scales, and filling in
 diary cards and contact cards as required.

 4. Participants' legal guardians should be able to communicate well with
 investigators, understand and comply with the requirements of this trial.

 5. Axillary temperature ≤37.0℃.

 -  Exclusion Criteria:

 1. Contraindications for vaccination.

 2. History of allergy to vaccines or drugs.

 3. History of Epidemic Cerebrospinal Meningitis.

 4. Immunization with any Group A meningococcal conjugate vaccine or
 polysaccharide vaccine within 12 months.

 5. Preterm birth at birth (before 37th week of pregnancy) or low birth weight
 (birth weight < 2300g for girls and < 2500g for boys);

 6. They were vaccinated with live attenuated vaccine within 14 days before
 vaccination and subunit or inactivated vaccine within 7 days (copy of
 vaccination certificate of subjects);

 7. Participants with convulsion, epilepsy, encephalopathy and psychiatric
 history or family history of epilepsy.

 8. Participant who has congenital heart disease, congenital malformation,
 Down's syndrome, sickle cell anemia or severe diseases with previous
 clinical manifestations that need to be excluded, including but not limited
 to nervous system, genetic defect disease (such as faba bean disease),
 cardiovascular system, blood and lymphatic system, immune system, kidney,
 liver, gastrointestinal tract, respiratory system, metabolism and bone
 system diseases, and History of malignant tumor.

 9. Those who developed acute disease or acute attack of chronic disease.

 10. Surgical removal of spleen or other important organs for any reason.

 11. History of thrombocytopenia or other coagulation disorders may cause
 contraindication of subcutaneous injection.

 12. Blood products such as immunoglobulin were received within 30 days before
 vaccination.

 13. Have received immunosuppressive therapy or other immunomodulatory drugs
 within 6 months before signing the informed consent form (Note: inhaled or
 topical hormone drugs, except those with an interval of 14 days or more from
 the date of signing the informed consent form).

 14. Those who participated in other clinical studies.

 15. Any other situations judged by investigators as not suitable for
 participating in this study.

 The Second stage study (A phase III clinical trial )

 -  Inclusion Criteria

 1. Healthy infants aged 6 to 15 months.

 2. Proven legal identity.

 3. Participants' legal guardians should understand the contents of the informed
 consent form, the vaccine in this trial, voluntarily sign the informed consent
 form, and be capable of using thermometers, scales, and filling in diary cards
 and contact cards as required.

 4. Participants' legal guardians should be able to communicate well with
 investigators, understand and comply with the requirements of this trial.

 5. Axillary temperature ≤37.0℃.

 -  Exclusion Criteria:

 1. Contraindications for vaccination.

 2. History of allergy to vaccines or drugs.

 3. History of Epidemic Cerebrospinal Meningitis.

 4. Immunization with any Group A meningococcal conjugate vaccine or polysaccharide
 vaccine within 12 months.

 5. Preterm birth at birth (before 37th week of pregnancy) or low birth weight (birth
 weight < 2300g for girls and < 2500g for boys);

 6. They were vaccinated with live attenuated vaccine within 14 days before
 vaccination and subunit or inactivated vaccine within 7 days (copy of vaccination
 certificate of subjects);

 7. Participants with convulsion, epilepsy, encephalopathy and psychiatric history or
 family history of epilepsy.

 8. Participant who has congenital heart disease, congenital malformation, Down's
 syndrome, sickle cell anemia or severe diseases with previous clinical
 manifestations that need to be excluded, including but not limited to nervous
 system, genetic defect disease (such as faba bean disease), cardiovascular
 system, blood and lymphatic system, immune system, kidney, liver,
 gastrointestinal tract, respiratory system, metabolism and bone system diseases,
 and History of malignant tumor.

 9. Those who developed acute disease or acute attack of chronic disease.

 10. Surgical removal of spleen or other important organs for any reason.

 11. History of thrombocytopenia or other coagulation disorders may cause
 contraindication of subcutaneous injection.

 12. Blood products such as immunoglobulin were received within 30 days before
 vaccination.

 13. Have received immunosuppressive therapy or other immunomodulatory drugs within 6
 months before signing the informed consent form (Note: inhaled or topical hormone
 drugs, except those with an interval of 14 days or more from the date of signing
 the informed consent form).

 14. Those who participated in other clinical studies.

 15. Any other situations judged by investigators as not suitable for participating in
 this study.