I've had a look at a few sites but can't seem to find a definitive answer as to whether you need any vaccinations when visiting China and Hong Kong. Mr Spudqueen is visiting Shenzen which is in China but just over the border from Hong Kong. Myself and teenage Spuds are joining him in Hong Kong.
I went last year (Shanghai and Hangzhou plus Hong Kong) and didn't have any vaccinations; nor did anyone ask me if I had. I think as long as you aren't going into remote provincial villages, and take the usual precautions with your food (nothing undercooked and drink bottled water) you should be fine.