Immunogenicity and safety of diphtheria-tetanus vaccine in pre-adolescent and adolescent South Koreans.

This study was conducted to compare the immunogenicity and safety of diphtheria-tetanus (Td) vaccine between pre-adolescents aged 11-12 years and adolescents aged 13-18 years. A total of 277 subjects (132 pre-adolescents and 145 adolescents) participated. After vaccination, all subjects (100%) in both groups exhibited seroprotective antibody levels (> or =0.1I U/mL) against diphtheria or tetanus toxoids. Although local adverse events following vaccination were more frequently observed in the pre-adolescent group than in the adolescent group (p=0.006), these events resolved within 7 days. Our study shows Td vaccination at age 11-12 years to be immunogenic and tolerable.