I had a young mare who spent time in hospital as an 11 month old, where she was on IV fuids and medication. Lots of jabs. Since then she has been very difficult about needles (any size ... it is the "idea" that sets her off).
She is perfect for everything else, and no problem for worming or oral meds.
Once I had my farrier hold her, and twitch her. Within about 15 seconds, she entered "the zone". I popped 2 vaccine needles in - mot even a flinch.
Since then I have had the farrier again twitch her (I am alone, so cannot hold to twitch and also handle the needles - not enough arms) for shots again. No objection whatsoever. When we release the twitch, she is fine, not "insulted" or angry.
Maybe I'm just lucky to find that solution, sure am happy about it.