Two injections of diphtheria-tetanus-pertussis-polio vaccine as the backbone of a simplified immunization schedule in developing countries.

From studies of antibody levels induced against poliovirus types 1, 2, and 3 and against diphtheria and tetanus toxins as well as from epidemiologic studies comparing the protective effect in children of two and three doses of diphtheria-tetanus-pertussis (DTP) vaccine, respectively, it can be concluded that two injections of DTP-polio vaccine administered at least four months apart will induce immunity against the four diseases. An immunization schedule can be built up in which bacille Calmette-Guérin (BCG) vaccine is given simultaneously with the first DTP-polio injection at the age of three to eight months and vaccination against measles and--if needed--yellow fever is performed simultaneously with the second DTP-polio immunization at the age of nine to 14 months.