Vaccine tips?

I’m sure I’m not alone in this, but now that my son is 3 1/2 he has started associating getting vaccinated with a horrible painful process. He had one today and yelled and called the nurse “dummy” (we’re working on his manners 🤦🏼‍♀️). He was fine right after and it was super quick so I think mostly he just works himself up about it.

Does anyone have any tips for getting a child comfortable with this? Something like misdirection, explanation tips, bribery (kinda kidding about this one but hey if it works...).

I just don’t want him to freak out about it but I’m not sure how to improve his comfort either.

I’ve tried having discussions as to why we get them. Told him how other members of our family get them too. Tried even explaining it’s fine to be upset but not fine to yell and call people names. But he’s three and in the moment probably isn’t remembering any of that.

So any tips or will it just take some maturation before he’s okay with it?