I never had a milk allergy and one week after my J&J vaccine I had a severe milk allergy.
Red blotches all over my body and itched like a 2 day old sunburn.
Especially wrists and ankles.
This trend of previously-unapparent allergies manifesting post-vaccine is very interesting.
It may be tied to an increase in sensitivity to allergens.
It may be tied to an acceleration of inflammation and other reactions to allergens.