When i first arrived in China I broke out in a rash all over my legs. I have no idea what caused it but I took an antihistamine for a couple of days and it went away. You could try finding a medicine similar to Benedryl.
The Hep A vaccine has to be done 2 shots. The first one is good for 6 months to a year and the second shot is good for 20 years. I got my first one more than a year ago so I might need to start it all over again. Stupid!