Observation of Immune Persistence in a Clinical Trial of an Adsorbed Tetanus Vaccine

Observation of Immune Persistence in a Phase III Clinical Trial of an Adsorbed Tetanus Vaccine

This study included 240 trial participants who had previously taken part in a Phase III clinical trial of an adsorbed tetanus vaccine (Protocol No.: CTP-TTVA-001), with 120 participants in each of the treatment and control groups. All trial participants were required to provide 3.0-4.0 mL of blood for an immunodurability assessment 2.5 years after vaccination.

Inclusion Criteria:

• Individuals who have previously participated in the Phase III clinical trial of the adsorbed tetanus vaccine (Protocol No.: CTP-TTVA-001).
• Willing to provide identification documents.
• Have given informed consent, voluntarily signed the informed consent form, and are able to comply with the requirements of the clinical trial protocol.
• At least 2.5 years have elapsed since completion of the vaccination series.

Exclusion Criteria:

• Following vaccination in the Phase III clinical trial (Protocol No.: CTP-TTVA-001), participants who have received tetanus immunoglobulin, tetanus antitoxin, or a vaccine containing tetanus toxoid antigen.
• Participants in the previous Phase III clinical trial (Protocol No.: CTP-TTVA-001) who did not complete the blood draw 30 days after vaccination.
• Other circumstances deemed by the investigator to render a participant ineligible for this clinical study.