DPT vaccine
The DPT vaccine or DTP vaccine is a class of combination vaccines against three infectious diseases in humans: diphtheria , pertussis ( whooping cough ) , and tetanus . 
<triplet> DPT vaccine <subj> vaccine <obj> instance of <subj> diphtheria <obj> vaccine for <subj> pertussis <obj> vaccine for <subj> tetanus <obj> vaccine for