Just wanted to put in my experience: I had the meningitis vaccine when first going off to college, just a few months before knowing that I had PANDAS. We knew something was up with my body, obviously, and debated the vaccine but decided to go for it. I didn't experience a reaction for that. I was happy to have it this past year when there was a small outbreak of meningitis at one of the colleges in my city; I felt protected. For me, based on my symptoms, a PANDAS exacerbation is better than Meningitis and I would probably risk it again if I was ever living back in a dorm situation.
Now with other ones, like the chicken pox vaccine I got a letter of exemption from my PANDAS doc via e-mail, no appointment needed. Technically I'm not allowed on campus if there's a chicken pox outbreak (yeah, ok, I'm sure the chicken pox police will be around to enforce that one), but to meet I'd rather risk maybe getting the chicken pox to maybe having vaccine reaction.
I've done very well with vaccines, only had one bad reaction as a child that spurred on PANDAS symptoms. My doctors are great about planning them, only doing one at a time, and making sure my immune system is not engaged if I'm going to need one. I do need a Tetanus booster soon. I've been putting it off, but I feel like it will likely be fine if we plan ahead.
So, like with all treatment, risk-benefit. To me, Meningitis and Tetanus are scarier than PANDAS. Chicken pox, not so much...