Having lived in china too, I would recommend tetanus booster, mmr booster, and hep a and b. hep b is a three shot series. These are all precautionary though, in the big cities you shouldn't have a problem. Regarding the flight... I've flown united 889/888 a ton of times. What can I say, it's united and not the best product. Bring your own entertainment...there is no avod or seatback screens. Also bring food as I never find their food to be enough. Next time, try to fly OZ via ICN...