Reactogenicity and immunogenicity of reduced antigen content diphtheria–tetanus–acellular pertussis vaccine (dTpa) administered as a booster to 4–6 year-old children primed with four doses of whole-cell pertussis vaccine

Abstract A trial to compare the reactogenicity and immunogenicity of a reduced antigen content diphtheria–tetanus–acellular pertussis (dTpa) vaccine with diphtheria–tetanus–whole-cell pertussis (DTPw) vaccine was conducted in Thailand. Three hundred and thirty children aged 4–6 years, primed with four doses of DTPw, received a single injection of either dTpa or DTPw. There was a significantly lower incidence of local and general reactions following dTpa than DTPw ( P