To Evaluate Safety and Preliminary Immunogenicity of the Diphtheria-Tetanus-acellular Pertussis Component Combined Vaccine in Children Aged 2 Months to 6 Years: A Randomized, Blinded, Active-controlled Phase I Clinical Trial
This study is a randomized, blinded, active-controlled phase I clinical trial to evaluate the safety and preliminary immunogenicity of the Diphtheria-Tetanus-acellular Pertussis Component Combined Vaccine (DTacP) in subjects (aged 2 months to 6 years). Primary safety endpoints are the occurrence of solicited adverse events within 30 minutes after each dose, the occurrence of solicited adverse events within 7 days after each dose, the occurrence of unsolicited adverse events within 30 days after each dose, and the occurrence of adverse events 30 days after immunization. The secondary safety endpoint is the occurrence of serious adverse events (SAEs) within 12 months after immunization. Secondary immunogenicity endpoints are the geometric mean concentration (GMC), geometric mean fold increase (GMFI), seropositive rates, seroconversion rates, or 4-fold increase rates of anti-DT, anti-TT, anti-PT, anti-FHA, and anti-PRN antibodies 30 days after immunization. The exploratory endpoints are the GMC, GMFI, seropositive rates, seroconversion rates, or 4-fold increase rates of anti-DT, anti-PT, and anti-FHA neutralizing antibodies 30 days after immunization in all groups, the GMC and seropositive rates of anti-DT, anti-TT, anti-PT, anti-FHA, and anti-PRN antibodies 12 months after primary immunization in the infant group, the seropositive rates and geometric mean tie (GMT) of anti- type I, type II, type III poliovirus neutralizing antibodies 30 days after immunization in all groups, the seropositive rates and geometric mean tie (GMT) of anti- type I, type II, type III poliovirus neutralizing antibodies 12 months after primary immunization in the infant group.
• Age Requirement: children aged 6 years, toddlers aged 18-24 months, and infants aged 2-3 months at the time of enrollment
• Previous Vaccination Requirements: (a) Children (aged 6 years) enrolled in the study should have received four doses of the Diphtheria, Tetanus, and Pertussis combined vaccine, and not yet received the Diphtheria, Tetanus combined vaccine; (b) Toddlers (aged 18-24 months) enrolled in the study should have received three doses of Diphtheria, Tetanus, and Pertussis combined vaccine as well as three doses of the Polio vaccine, and not yet received the booster dose of Diphtheria, Tetanus, and Pertussis combined vaccine and the Polio vaccine; (c) Infants (aged 3 months) enrolled in the study should not have received diphtheria-tetanus-pertussis-containing vaccine, polio-containing vaccine, 13-valent pneumococcal polysaccharide conjugate vaccine, Haemophilus influenzae type b conjugate vaccine, or meningococcal group A and C polysaccharide conjugate vaccine; (d) Infants (aged 2 months) enrolled in the study should not received diphtheria-tetanus-pertussis-containing vaccine, polio-containing vaccine, 13-valent pneumococcal polysaccharide conjugate vaccine, or Haemophilus influenzae type b conjugate vaccine.
• Provision of Legal Identification: Volunteers and their legal guardians or appointed representatives must provide valid legal identification documents.
• Informed Consent: Legal guardians or appointed representatives of volunteers must have the capacity to understand the informed consent document and the research process, voluntarily participate, sign the informed consent form, and be able to comply with the requirements in the study as well as complete relevant visits on time.
• Birth Outcome Condition: Toddlers (aged 18-24 months) and Infants (aged 2-3 months) should be born at full term (37-42 weeks of gestation) with birth weight ≥2500g.
• Temperature Requirement: Axillary body temperature is no more than 37.3°C.