Hi, I had gone through your question and understand your concerns.
Whole cell DPT( DTwP) ( so called painful injection ) is slightly better or equal  in terms of immunity for 
pertussis in long term ,  main reason for use of so called painless vaccine( DTaP)  was due to less local and systemic side effects  of pain , swelling , tenderness , 
fever and irritability . Moreover painless injections are in short supply ( not available ) presently .
 So in terms of effectiveness painful DPT is more or equal effective than painless DPT . Go for DTwP ( painful ) vaccine as suggested by your doctor  , give baby 
paracetamol 6-8 hourly for 2 days  to decrease pain and fever . Routinely I do recommend DTwP (painful ) at least for primary series of vaccines  .
Hope this answers your question. If you have additional questions then please do not hesitate in writing to us.
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