A Clinical Study on Immunogenicity Persistence of Adsorbed 5-component Acellular Pertussis, Diphtheria and Tetanus Combined Vaccine

This clinical trial will enroll 160 participants who previously took part in the Phase I clinical trial of the adsorbed acellular pentavalent (five-component) DTP-polio combination vaccine (for individuals aged 6 years and older) (Protocol No.: CTP-Tdcp-001). Approximately 3-4 mL of venous blood will be collected from each participant 2.5 years, 5 years, and 10 years after vaccination for a study on immune persistence.

Inclusion Criteria: * Participants in the 6-11-year-old, 12-17-year-old, and ≥18-year-old groups from the Phase I clinical trial of the adsorbed acellular pentavalent (five-component) DTP-polio combined vaccine (for individuals aged 6 and older) (Protocol No.: CTP-Tdcp-001) who were included in the protocol-defined analysis set; * Willingness to provide identification documents; * Informed consent must be obtained from the trial participant and/or guardian and/or authorized representative, and the informed consent form must be signed; * The trial participant and/or guardian and/or authorized representative must be able and willing to comply with the requirements of the clinical study protocol and be able to complete the full course of study follow-up. Exclusion Criteria: * Received another DTP-type vaccine after completing the CTP-Tdcp-001 study; * Developed a DTP-related illness since the completion of the CTP-Tdcp-001 study; * Has a coagulation disorder; * In the investigator's judgment, the participant has any other factors that make them unsuitable for participation in the clinical trial.