Pertussis toxin

Researchers don’t guess how to make mice allergic to a food protein.

They use tools that work:
• aluminum
• active pertussis toxin (histamine-sensitizing factor / HSF)

In classic work, about 0.1 nanogram of active HSF could boost allergy-type antibodies (Munoz).

DTaP contains aluminum plus pertussis toxin that was chemically turned off.
That does not mean leftover “still-on” HSF is zero.

Lots are checked in mouse histamine tests against older “acceptable” batches.

Published testing on marketed shots has found residual activity in a low-but-real range (on the order of up to about 2 IU per dose in collaborative work)—and some lab methods can detect roughly ~5 ng of spiked active toxin in a toxoid vaccine mix.

There is no published infant “safe leftover” limit in nanograms.

So DTaP sits on the same mechanistic street as the lab allergy recipe: aluminum, plus pertussis toxin protein, plus leftover activity that is limited—not erased.

In a decades-long explosion of food allergy, that makes DTaP a serious suspect—not a footnote.