Abstract:Objective: To evaluate the safety and immunogenicity of booster immunization of adsorbed tetanus vaccine developed by Olymvax Biological Technology co., LTD in adults. Methods: This study was divided into two phases. For the first phase, openly design was adopted to evaluate the safety of experimental vaccine and the second phase would be performed if the vaccine was confirmed to be safety. The second phase of this study was designed to be a single center, randomized, double-blinded, paralleled controlled clinical trial. Health residents aged 18 to 30 years old were recruited to receive one dose of experimental adsorbed tetanus vaccine and control vaccine. Daily diary was used to collect safety data. Blood samples were collected right before and 28 days after vaccination for Tetanus toxoid antibody detection through standard enzyme linked immunosorbent assay. Results: Thirty participants were enrolled in the first phase of clinical trial. Frequency of total adverse reactions (AR) observed within 7 days after vaccination was 33.3%. In the second phase of clinical trial,1 200 participants were enrolled with 600 participants in experimental vaccine and control group, respectively. Incidences of total AR were 30.7% and 31.5% for vaccine and control group, respectively. Most common injection-site AR was pain, while most common systemic AR was fever. No statistically significant differences of frequencies of AR were found between treatment groups. For both group, good immunological response was induced, with proportion of participants with antibody concentration ≥0.1 U/ml for both groups up to 100% and GMCs were 3.38 U/ml and 3.16 U/ml, respectively. Conclusion: Adsorbed tetanus vaccine developed by Olymvax Biological Technology co., LTD showed good safety and immunogenicity, which is applicable for booster immunization for adults, and for further developing of combined vaccine.