My 4-year-old is going to have his vaccinations. It seems like when they are younger, you can handle it better. Sow that he is older, and understands more concepts, are there any tricks or things you can do to make the 3 shots better?
I have talked to him about it and he pretends he understands, but I know he does not really understand. I think I am freaking out more than he would be, only because he does not know what he is going to go through.
I would not spend a lot of time and effort "preparing" him - that way you risk building it up in his mind into a big scary thing. A huge part of pain perception is to do with psychological state and expectations of pain - if you expect something to hurt, it will hurt more than if you don't.
So: don't mention it until the day, or even until you're setting off to the medical centre or wherever, then say "Hey, today we're going to get your vaccinations" (you might want to use a more 4-yo-friendly word like "vax", "jabs", "shots" etc.). When he says "what's that" you can go into a nice spiel about how it is to help his body fight off bad invaders that might try to get in. Good learning opportunity for explaining about the immune system and so on.
99% likely he won't even ask "will it hurt", but if he does, you can just say "it's just a little scratch for a moment when it goes in, but it's very soon over".
First, you need to calm down about it yourself. Children cue off their parents' reactions. If you're freaked out, he will be too. The mildest disease is 100 times worse than a shot.
Second, don't lie about what it will be like, or else every time you go to a doctor he will expect the worst. Tell him the facts without either sensationalizing or minimizing. If he's the kind of person that gets scared easily, put off telling him until you're on the way to the doctor. Anticipation makes it worse.
Third, give him something else to concentrate on. Say something like, "It hurts, but it will hurt more if you wiggle too much. Look at me and try to stay as still as you can and relax your arm."
Lastly, some kids are going to have a hard time no matter what you do, so just get it over with as quickly as possible and remain calm yourself. My daughters cry during the event, but stop pretty much immediately after they're sure it's done. My son starts flipping out, screaming, and thrashing as soon as the needle comes out, and he stops listening to us, so about all we can do is hold him down so the needle won't break off inside him. He doesn't calm down until we're in the car, and he complains about the shot all day. We prepare all our kids in the same way. Sometimes it's just plain out of your hands.
The key to lessening pain of a vaccination is not to tense up your muscles. I had my kids practice "make your arm soft" and poke them with my finger. It's easy to demonstrate that a simple finger poke hurts more on a tense arm than a soft one. Then just as the doctor or nurse approaches their arm with the needle, remind them "make your arm soft" and it should hurt little or not at all.
If they have pain and swelling afterwards give them a children's painkiller. Some kids do react poorly to the DPTP especially.
When I need an annual flu shot or other vaccination, I like to bring my son with me (schedule permitting) so he can watch. Seeing me go through it, understand that we all have to do it, and that it's not a big deal or especially painful, makes it less of an anxiety when he needs to have one himself.
We also discussed often (even at age 4) the purpose of vaccinations, and how because of vaccinations many awful diseases are now extremely rare.
Maybe try talking to him about being brave and having courage. How he's a big boy now and he can be very brave, like a super hero that he may like.
Do not make a big deal of the vaccinations, say it's 3 pinches, it will pinch for a little bit and it will be over soon. Reassure him that you'll be there with him and will hold him tight.
Then you could reward him with something that he does rarely but likes a lot. For example you could say that if he's a big brave boy you will take him to get a frozen yogurt treat after the doc visit.
Good luck!
Some great answers already about explaining the purpose of vaccinations, but this is what I actually do on the day:
Show him the sweeties that he is going to get once he's had his shots.
Get them out of your bag as the needle appears (this distracts him from the needle, so his arm is less tense, so it hurts less).
In most cases the shot should be done by now. If not then, in a humorous tone, ask the nurse/doctor to hurry up with that shot, because little Johnny wants to have his sweetie!
Apply sweetie to child.
GOTO 1 UNTIL all-shots-complete.
Cuddle child, distract child.
Give yourself a sweetie, 'for helping'.
Well my child understands shots. By 4yrs old they understand lots. I just told my daughter that since she was turning 4yrs old she had to get a shot and she just ask were would they give it and will these hurt. She is able to tell you what the allergy MD does and the regular MD. She even asks me if this time at the dentist is xray time because she doesnt like the xray. I think its all about conversation. Sit, explain and let them tell you how they feel and answer any questions with the truth. She tells me shots hurt but only for a minute.
