Did they abandon the DPT shots??
No, but lots of people are afraid of a severe reaction to the pertusis component, and opt out.
Two of my three children had the full sequence of DPT's, but my older son had the reaction everyone is afraid of to the first (uncontrollable crying is the main sign in infants), and consequently didn't take the rest (later ones could be fatal since the immune response has been primed).
I suspect if it were only folks who opted out after a reaction to the first we'd have enough kids vaccinated to have 'herd immunity' (as the term of art goes), but that's not the case.