The immunogenicity and reactogenicity of Td booster vaccination in Korean preadolescents, aged with 11-12 years old

A Phase III Study to Evaluate the Immunogenicity and Safety of GC1107 (Adult Tetanus Diphtheria Vaccine) in Healthy Adults

BACKGROUND

This study was conducted to assess the immunogenicity and safety of GC1107 (adult tetanus diphtheria [Td] vaccine). The primary goal was to evaluate the non-inferiority of the immunogenicity of GC1107 compared to the control vaccine. Additionally, the safety profiles of GC1107 and the control vaccine were compared.

METHODS

The subjects were adults ≥ 18 years old who were not injected with Td or adult tetanus-diphtheria-pertussis (TdaP) vaccine within the recent 5 years. A total of 253 subjects were enrolled and randomized to either the GC1107 group or the control group. For immunogenicity assessment, blood samples were collected at baseline and 28 days after vaccination and antibody titer of diphtheria and tetanus were assessed.

RESULTS

The seroprotection rates of diphtheria and tetanus were 89.76% and 91.34%, respectively, in the GC1107 group, and 87.80% and 86.99% in the control group. The geometric mean titer (GMT) of the anti-diphtheria antibody increased after vaccination in both groups, showing no significant difference between the groups (P = 0.139). The anti-tetanus GMTs after vaccination also showed comparable increases in both groups, and showed no significant difference (P = 0.860). In the safety evaluation, solicited local adverse reactions occurred in 81.2% of the subjects in the GC1107 group and in 86.4% of the subjects in the control group. Solicited systemic adverse events occurred in 33.2% of the subjects in the GC1107 group and in 47.2% of the subjects in the control group, which did not reach statistical significance.

CONCLUSION

This phase III study demonstrated non-inferiority in immunogenicity and comparable safety of GC1107 compared with the control Td vaccine.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02361866.

Clinician awareness of tetanus-diphtheria vaccination in trauma patients: a questionnaire study

Background

Most trauma patients visit the hospital via the emergency department. They are at high risk for tetanus infection because many trauma patients are wounded. Tetanus immunity in the Korean population has been revealed to be decreased in age groups over 20 years old. It is important for emergency physicians to vaccinate patients with the tetanus booster in wound management.

Methods

Questionnaires were sent to the directors of the emergency departments of resident training hospitals certified by the Korean Society of Emergency Medicine.

Results

Two thirds of the emergency department directors surveyed reported applying tetanus prophylaxis guidelines to more than 80% of wounded patients. However, about 45% of clinicians in the emergency departments considered giving less than half of the wounded patient tetanus booster vaccinations, and there were no distinct differences in tetanus booster vaccination rates among different age groups. Most emergency physicians are familiar with tetanus prophylaxis guidelines for wound management. However, more than half of the emergency department directors reported that the major reason for not considering tetanus-diphtheria vaccination was due to assumptions that patients already had tetanus immunity.

Conclusion

Attitude changes should be encouraged among emergency physicians regarding tetanus prophylaxis. As emergency physicians are frequently confronted with patients that are at a high risk for tetanus infection in emergency situations, they need to be more informed regarding tetanus immunity epidemiology and encouraged to administer tetanus booster vaccines.

Immunogenicity and safety of diphtheria-tetanus vaccine in adults

This study was conducted to evaluate the immunogenicity and safety of diphtheria-tetanus (Td) vaccine in adults over 40 yr old who had never received a diphtheria-tetanus-pertussis (DTP) vaccination. A total of 242 subject completed three-doses of Td vaccination and subsequent assays for immunogenicity. Before vaccination, 33.9% and 96.7% participants showed antibody levels of diphtheria and tetanus, respectively, which were below protective level (<0.1 U/mL). After the first dose of Td vaccine, 92.6% and 77.6% of subjects gained protective antibody concentrations (≥ 0.1 U/mL) for diphtheria and tetanus, with an increase to 99.6% and 100% after the third dose. Local and systemic adverse events occurred in 37.9% and 15.5% of the subjects. No serious adverse event requiring an unscheduled hospital visit occurred. In conclusion, three-doses of Td vaccination to unimmunized adults are safe and effective in inducing protective immunity against diphtheria and tetanus.