Hypnotherapy

I don’t think hypnosis is the solution, but here are some other practical thoughts, which may or may not be worth thinking about.   It’s probably an amalgamation of multiple strategies.  Something here might trigger a useful thought for you.

1. Is there a friend of more or less his own age who will go with him and who doesn’t fear needles?
2. I believe there are breathing exercises that can help in any stress situation. Would it work if you all have these, as a family (so he doesn’t feel singled out), and do it without mentioning needles or vaccines (except, perhaps, privately, to the therapist)? 
3. Try to avoid turning it into a big parent / child issue, because that’s a cycle that’s difficult to break out of.
4. If you do manage to get him to go, distraction sometimes works on phobias. Take a tablet or laptop and play his favourite TV show, maybe?  
5. Get into some mindfulness and meditation, but again, perhaps don’t mention why. Just say you’re doing it, as a family, and see if you can get someone he relates to, of his own age, involved.  That definitely works on phobias and by coincidence it’s a bit of ‘thing’ with some of the younger generation atm (I was part of a mindfulness group of six in which three were under 18).  If he can just become used to that it may perhaps help him when you do eventually suggest he uses it at the doctors??  Others on this platform may know more about whether this works well for autistic people???
6. Some therapists suggest making people think about the worst that could possibly happen with an injection (a bit of tiny localised pain at most), and without it (lengthier discomfort and perhaps more serious illness, for him or other members of the family). I’m not sure about that one for someone on the spectrum.
7. What may work better, apparently, is a patient person explaining what is going to happen and how, and it’s suggested demonstrating on an orange. Then getting the child to inject the orange, just with water, a few times, until they become familiar with the whole process. 

Best wishes and good luck with it.   

I don’t think hypnosis is the solution, but here are some other practical thoughts, which may or may not be worth thinking about.   It’s probably an amalgamation of multiple strategies.  Something here might trigger a useful thought for you.

1. Is there a friend of more or less his own age who will go with him and who doesn’t fear needles?
2. I believe there are breathing exercises that can help in any stress situation. Would it work if you all have these, as a family (so he doesn’t feel singled out), and do it without mentioning needles or vaccines (except, perhaps, privately, to the therapist)? 
3. Try to avoid turning it into a big parent / child issue, because that’s a cycle that’s difficult to break out of.
4. If you do manage to get him to go, distraction sometimes works on phobias. Take a tablet or laptop and play his favourite TV show, maybe?  
5. Get into some mindfulness and meditation, but again, perhaps don’t mention why. Just say you’re doing it, as a family, and see if you can get someone he relates to, of his own age, involved.  That definitely works on phobias and by coincidence it’s a bit of ‘thing’ with some of the younger generation atm (I was part of a mindfulness group of six in which three were under 18).  If he can just become used to that it may perhaps help him when you do eventually suggest he uses it at the doctors??  Others on this platform may know more about whether this works well for autistic people???
6. Some therapists suggest making people think about the worst that could possibly happen with an injection (a bit of tiny localised pain at most), and without it (lengthier discomfort and perhaps more serious illness, for him or other members of the family). I’m not sure about that one for someone on the spectrum.
7. What may work better, apparently, is a patient person explaining what is going to happen and how, and it’s suggested demonstrating on an orange. Then getting the child to inject the orange, just with water, a few times, until they become familiar with the whole process. 

Best wishes and good luck with it.