I had no problems at all with my hep B vaccination, but I was also offered a hep A vaccination, and that hurt like hell. I was in so much pain I didn't know what to do with myself. Apparently it's not usual to have such a reaction, but it stopped after about 4 hours, and I'm still alive several years later.
The recent discussion of STDs brought up a couple of questions for me, which I asked at my last clinic appointment. If anyone's interested, this is what I found out.
1. I asked if Hep B could be contracted via oral, and the answer was "yes, definitely". So, all those people out there who aren't vaccinated, do be careful! Apparently it's a horrid disease.
2. I asked if CIM increased the risk of catching STDs via oral without. The answer was that she couldn't quote any studies off the top of her head, but based on anecdotal evidence, yes it does make a difference. She much less often treats someone who's caught something just through pre-cum. Her theory was that ejaculation flushes the bad stuff out of his urethra and into your mouth. I've got a feeling that only applies to the bacterial ones, though. Don't viruses live in the fluid itself, rather than just being picked up by it?