If it helps 2 of my family members have epilepsy, one of them severe epilepsy which they've been medicated for for 30 years and occasionally causes grand mal seizures that land them in intensive care, and they've both had jabs and didn't even have any side effects.
If you're concerned about interactions with medication that's why they ask you to contact them if you have concerns, and ask you when you go in if you're on owt or have any reactions to certain medications.
I'm allergic to aspirin, ibuprofen etc, so I asked if I was ok having it before I went.