I am not aware of any neurological impediment to the vaccines, other than no-one with a fever, recent covid or recently recovering from significant surgery needs to delay vaccination by a few weeks. I can't thnk of any permanent contra-indications unless someone has a dual allergy condition for both of the main vaccine types (there are statistically 6 adults in the UK in this category). There are other reasons to steer people from one vaccine to another but in essence everyone can have a vaccine. Thye are not a "live" vaccine so the usual impediments don't apply.

Edit: here is the ABN's guidance on this:
https://www.theabn.org/resource/coll...ons_9.1.21.pdf


But I guess it's a case of waiting until vaccinations get the virus to such a level that we won't need to worry about restrictions like this, so they then fall by the wayside.