This study included 180 trial participants who had previously taken part in the Phase IIIb clinical trial of the ACYW135 group meningococcal polysaccharide-conjugated vaccine (CRM197 carrier) for children aged 4-6 years (Protocol No.: CTP-MCVF-002) and had completed blood sample collection at 90 and 180 days post-vaccination; there were 90 participants in each of the treatment and control groups. All trial participants were required to provide 3.0-4.0 mL of blood samples for immunopersistence assessment at 3 and 5 years post-vaccination, respectively.
Individuals who previously participated in the Phase IIIb clinical trial of the ACYW135 group meningococcal polysaccharide-conjugated vaccine (CRM197 carrier) for children aged 4-6 years (Protocol No.: CTP-MCVF-002) and were included in both the IPS1 and IPS2 analysis sets
Willing to provide identification documents
Willing to provide informed consent, voluntarily sign the informed consent form, and comply with the requirements of the clinical study protocol
The interval since completion of the vaccination series must be at least 3 years
Received another meningococcal vaccine after completion of the CTP-MCVF-002 trial
Has thrombocytopenia, any coagulation disorder, or is currently receiving anticoagulant therapy
Has a history of meningitis since the end of the CTP-MCVF-002 trial
Other conditions deemed by the investigator to make the subject ineligible for this clinical study