Immunogenicity and safety of primary and secondary DTaP booster vaccination

Diphtheria-tetanus-acellular pertussis (DTaP) vaccination must currently be administered three times starting at 2 months of age, at intervals of two months, with the first and second boosters administered at 15 to 8 months and 4 to 6 years of age. A high rate of vaccination is maintained, but studies of the efficiency and safety of booster vaccination are lacking. This study evaluated the immunogenicity and safety of the DTaP booster vaccine. Seventy-two infants who had been vaccinated with the first booster and 78 children who had been vaccinated with the second booster were enrolled in this study. Local and systemic adverse reactions after vaccination were recorded. Sera obtained before and 1 month after booster vaccination were analyzed for antibodies to diphtheria and tetanus toxoid, and anti-pertussis toxin. Diphtheria: The GMT was increased. Tetanus: The geometric mean antibody titer (GMT) was increased. Pertussis: The GMT was increased by 13.72 times and 14.37 times after the first and the second additional vaccination, respectively. Although the seroconversion rate was low prior to the first booster, the average amount of anti-pertussis toxin antibodies before the first additional vaccination was 143.37 EU/mL, which rose to 261.88 EU/mL after the vaccination. The seroconversion rate also increased to 100%. Adverse reactions showed spontaneous resolution within a few days after vaccination. After the second additional vaccination, there was a statistically significant increase in the manifestation of myalgia compared to after the first additional vaccination. In conclusion, DTaP booster vaccination was effective in Korean children, demonstrating that modifications to the current regimen would be unnecessary.

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

PURPOSE: This study was undertaken to evaluate the immunogenicity and reactogenicity of Td booster immunization in early preadolescents of Korea. METHODS: Healthy preadolescents, who had been vaccinated with 4 or 5 doses of DTaP vaccines until 6 years old age, were enrolled in this study from August 2006 to April 2007 . Diphtheria and tetanus anti-toxoid antibodies in sera were measured by ELISA just before vaccination and 4 weeks after vaccination to evaluate immunogenicity. Local and systemic adverse reactions observed for 4 weeks after vaccination to access reactogenicity. RESULTS: 183 preadolescents were enrolled and mean age was 11.40+/-0.51 years old. All subjects achieved seroprotective diphtheria and tetanus anti-toxoid antibodies (titers > or =0.1 IU/mL) after Td booster vaccination. Among 183 vaccinees, 73.8% showed local adverse reactions and 37.2% systemic adverse reactions. Pain at injection site (66.1%) was the most common local reaction, and the most commonly shown systemic reaction was myalgia (17.5%). The adverse reactions were spontaneously relieved within three days after vaccination. CONCLUSION: Td vaccine in this study was high immunogenic and showed an acceptable tolerance in Korean preadolescents. Td booster vaccination at 11 -12 years old is the most effective method to increase compliance of the vaccination and to decrease the incidence of diphtheria and tetanus.