While i was in China, i had a range of shot's but that was at the insistence of the companies i worked for. Some of my colleagues did suffer side effects from these shoots, and to be honest the areas of china where i was living and working, they were unnecessary.
What i would advise, if your going to be staying in a relatively rural area, is to take a decent supply of anti malaria drugs, and remember to continue taking them for the specified period after you return home.
The one thing you need to be very careful of, is the water in China, don't whatever you do drink it, unless it's been boiled for 3 minutes, or stick to bottled water. Don't forget, water is used for many things, one is ice keep that in mind. The other is for washing fruit and veg, ...this is where most westerners get caught out, and can pay dearly for it. The only way to be totally safe, is in the home, use boiled water (that's cooled or cold) to wash fruit and veg. The other is to refrain from eating fresh fruit and veg while out in restaurants etc, or buying drinks on the street, that's been made from fresh fruit. etc...
Remember, the local population have some immunity to these water bourne bugs, but even they can sercombe to some of these nasty bugs.... I can assure you, ...you wont want to get a dose of Shanghai trots on your trip!! Some of these bugs are very virulent and can knock you down for 5 days or more, others can knock you down for a day or two, but you'll feel weak and knackered for days after....BE CAREFUL and VERY AWARE!!
David......