DTaP immunization

DTaP immunization Diphtheria-tetanus-acellular-pertussis immunization, a vaccine that, like DTP, protects against diphtheria, pertussis (whooping cough), and tetanus. DTaP is the same as DTP, except that it contains only acellular pertussis vaccine, which is thought to cause fewer of the minor reactions associated with immunization. Acellular pertussis vaccine is also probably less likely than regular pertussis vaccine to cause the more severe reactions occasionally seen following pertussis vaccination. It is currently recommended that DTaP be given at 18 months and at 4 to 6 years of age. See also diphtheria; pertussis; tetanus.