The FCO gap year travel advice produced by the UK government foreign office is probably the defacto to place to go for updated country information. We take this with a pinch of salt though, As reading through some of the travel advice can fill you with absolute fear and dread prior to travelling.
They do have some very useful information on health advice however, and one of the most common questions we are asked is what vaccinations are required prior to travelling. As we are not doctors, we cannot give you accurate up-to-date information. You should check with your own GP or travel clinic that the FCO gap year travel advice service is definitely a good place to start.
The FCO gap year travel advice service also has information on current VISA requirements, and entry requirements into countries. So if you are off on Xtreme Gap Year trip, check out their website prior to travelling.