Newtown Community Chiropractic do a presentation every so often about immunisation. I haven't been to it myself, but I've been told by a friend that it's very well balanced, factual etc with the emphasis in being informed rather than influencing your choice. I'm on my phone so can't check where you are, but if you're not in Sydney I wonder if they would share the info if you contacted them. You can just google them.

Hope your little one is back to himself asap, I felt the same as you described after DD had her vacc's done.