Where about are you going? My sister lives in Shanghai and I am going to see her in December with my little one. Been to China several times and it is not as bad as you think. If you stay in the cities, you don't need special vaccinations. Re-visas, you can do an online application. Need to look for it myself so if you are interested, let me know.
Your DH is lucky. I've been to China 3 times and I thoroughly enjoyed each visit. I never had any vaccinations, although there is an issue over the quality of the drinking water. In the hotels I stayed in they provided bottled water to clean your teeth.