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

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 ≥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.