Enzyme-linked immunosorbent assay for detecting anti-pertussis toxin antibody in mouse

PURPOSE: Although the DTaP and Tdap vaccines used to prevent pertussis have been used for a long time, there is no standard method for measuring pertussis antigens. Therefore, this preliminary study was conducted to develop an enzyme-linked immunosorbent assay method using an animal model for measuring antibodies against pertussis toxin, the most important pertussis pathogenic antigen, in the sera of vaccinated mice. MATERIALS AND METHODS: Bordetella pertussis Tohama phase I was cultured for 24–30 hours, and then pertussis toxin was purified from the culture medium by chromatography. Purified pertussis toxin was diluted in phosphate-buffered saline-coating buffer, and 100 µL of diluted pertussis toxin was added to each well and reacted at room temperature for 4 hours. Positive serum was diluted to 1/1,250–1/80,000 and negative serum was diluted to 1/50 to determine the coating concentration with the optimal signal/noise ratio. Optimal test conditions were confirmed from the dilution factors of the secondary antibody and streptavidin horseradish peroxidase (SA-HRP). RESULTS: Optimal conditions were as follows: 4 µg/mL for coating antigen; 1/40,000 for secondary antibody; and 1/1,000 for the SA-HRP dilution factor. Comparison of the sera obtained from mice treated with a developing vaccine and commercial vaccine with National Institute for Biological Standard and Control standard serum under the established conditions showed the following results: 1,300.62, 534.94, and 34.85, respectively. CONCLUSION: The method developed in this study is suitable for measuring anti-pertussis toxin antibodies and may be applicable for clinical sample analysis or indirect diagnosis of pertussis.

Evaluation of Immunogenicity and Safety of the New Tetanus-Reduced Diphtheria (Td) Vaccines (GC1107) in Healthy Korean Adolescents: A Phase II, Double-Blind, Randomized, Multicenter Clinical Trial

This phase II clinical trial was conducted to compare the immunogenicity and safety of a newly developed tetanus-reduced diphtheria (Td) vaccine (GC1107-T5.0 and GC1107-T7.5) and control vaccine. This study was also performed to select the proper dose of tetanus toxoid in the new Td vaccines. Healthy adolescents aged between 11 and 12 yr participated in this study. A total of 130 subjects (44 GC1107-T5.0, 42 GC1107-T7.5 and 44 control vaccine) completed a single dose of vaccination. Blood samples were collected from the subjects before and 4 weeks after the vaccination. In this study, all subjects (100%) in both GC1107-T5.0 and GC1107-T7.5 groups showed seroprotective antibody levels (> or = 0.1 U/mL) against diphtheria or tetanus toxoids. After the vaccination, the geometric mean titer (GMT) against diphtheria was significantly higher in Group GC1107-T5.0 (6.53) and GC1107-T7.5 (6.11) than in the control group (3.96). The GMT against tetanus was 18.6 in Group GC1107-T5.0, 19.94 in GC1107-T7.5 and 19.01 in the control group after the vaccination. In this study, the rates of local adverse reactions were 67.3% and 59.1% in GC1107-T5.0 and GC1107-7.5, respectively. No significant differences in the number of adverse reactions, prevalence and degree of severity of the solicited and unsolicited adverse reactions were observed among the three groups. Thus, both newly developed Td vaccines appear to be safe and show good immunogenicity. GC1107-T5.0, which contains relatively small amounts of tetanus toxoid, has been selected for a phase III clinical trial.

Safety and Immunogenicity of a Pseudomonas aeruginosa Outer Membrane Protein Vaccine(CFC-101) : a Phase I/IIa Clinical Trial / 감염

BACKGROUND: We developed a Pseudomonas aeruginosa outer membrane protein(OMP) vaccine, CFC-101, and the prophylactic efficacy of which has been demonstrated in animal models. In order to evaluate the safety and immunogenicity of the P. aeruginosa vaccine, we carried out a phase I/IIa clinical trial in healthy male volunteers. METHODS: Groups of eight volunteers, including two placebo subjects, were vaccinated intramuscularly with three doses of 0.25, 0.5 or 1.0 mg of the vaccine at one week intervals. Signs of systemic and local reactions observed after vaccination were recorded for each vaccinee for 5 days. Physical examinations were performed on days 0, 1, 7, 8, 14, 15, 21, and 42, and clinical laboratory tests were done on days 0, 3, and 21. Blood samples for assay of serum antibody levels were obtained up to 42 days after the first vaccination. RESULTS: The vaccine was generally well tolerated by all vaccinees, showing no significant side effects. In the three dosage groups, all vaccinees, except one receiving the 0.25 mg dose, showed significant elevation in serum IgG antibody titers against the vaccine proteins, indicating 100% seroconversion in 0.5 and 1.0 mg groups. The human antibodies induced by the vaccine were specific for P. aeruginosa OMPs, as confirmed by western blot analysis and immunoprecipitation assays. The capacity of the human antisera to enhance opsonophagocytic killing activity by polymorphonuclear leukocytes and to confer protection against P. aeruginosa infections indicates that the antibodies elicited by the vaccine have protective efficacy. CONCLUSION: We conclude that the P. aeruginosa OMP vaccine is safe and effective for human use and its optimal dose to be 0.5 or 1.0 mg.