The DTaP vaccine given to an infant two months after birth is capable of harm.

Infanrix (DTaP) contains up to 100 µg Polysorbate 80 per 0.5 ml dose.

A 2-month old infant male in the 50th percentile weighs 5.5 kg.

Unit conversion yields

Infanrix polysorbate exposure

Let's compare this to the level of Polysorbate 80 exposure known to harm an animal.

From the Metabolism/Pharmacokinetics:Mechanism of Action section of this record we see the effect of various amounts of Polysorbate 80 per ml perfusion in guinea pigs

2.4 µg affected heart function
0.7 µg to 4 µg showed dose-related response
6.25 µg altered function of small intestine

A typical male guinea pig weighs 1000 g and water intake is approximately 10 ml per 100 g body weight per day (which equates to 100 ml per 1000 g guinea pig, or 100 ml/kg).

Assuming a perfusion equal to 10% of fluid intake (10 ml perfusion per kg rodent body weight), then unit conversion for Polysorbate 80 exposure yields

guinea pig polysorbate exposure

While rodent metabolism is not identical to human metabolism, this simplified calculation shows that an infant's exposure to Polysorbate 80 from a DTaP vaccination is in the realm of exposure shown to cause harm.