Booster vaccination at 6-8 years of age with a reduced antigen content dTpa-IPV vaccine is immunogenic and safe after priming with whole-cell pertussis vaccine

Pertussis vaccines containing reduced amounts of antigen have been considered primarily for use in adolescents and adults to date. We evaluated a reduced antigen content combined diphtheria tetanus acellular pertussis and inactivated polio vaccine (dTpa-IPV) in 6-8 year-old children in Taiwan, who had received four doses of DTPw (combined diphtheria, tetanus, whole cell pertussis vaccine) and OPV (oral polio vaccine). One month after the booster dose, seroprotection rates and vaccine response rates to all antigens were at least 98.8%, and significant increases in antibody concentrations were observed. Booster vaccination was associated with minor local reactions and systemic symptoms. Symptoms of severe intensity did not occur, with the exception of local pain. The dTpa-IPV vaccine was immunogenic and well tolerated in 6-8 year-old children and offers an alternative to the current use of tetanus and diphtheria vaccine and OPV in Taiwan, addressing the established need for repeated booster vaccinations against pertussis at the same time.