Hellbound
Merchant of Doom
Except! The one in the left arm (it was definitely not the one they said should have any after effects) had a very deep, slow throbbing pain for several days if not weeks.
This actually occurs in several vaccinations, generally the ones that use a live virus vaccine. I believe Yellow Fever and Typhus are both live virus, but I may be mis-remembering.
IN any case, the answer is simple. You had a mild infection there from the vaccination. General symptoms are a low fever, the injection site being sore, slightly inflamed, red, and possible warm to the touch. Should clear in a few days. Not all of these symptoms will occur, though.
Trust me, I've had vaccines for darn near every possible disease (being in the military, deployed to third-world locations, and a medic [we get extra ones, whopee!]). SOme of them you never really feel. SOme make my arm hurt for days (Anthrax). Some create the redness, soreness, and heat (Yellow Fever). Some created awful itching and a welt at the injection site (MMR). It depends on the vaccine, as well as whether it's something you've been exposed to before (my reaction to MMR was because I'd already been vaccinated before, but they lost my records so I had to do it again...my body's immune system said "hey, that's that bad stuff we remember from 10 years ago! Let's get it!).