Only because those are good ideas in the states too, as are many other periodic vaccinations.
Correct. Everyone who travels anywhere should have those vaccinations.
Typhoid and Malaria for Coz? Can you provide a link to where you got that?
For the basics, check out Health Information for Mexico | CDC Travelers' Health.
Typhoid Fever is fairly nasty and the immunization works well. The shot is quick and cheap, and typhoid is neither.
I am one of the few who bothers with Malaria prophylactic going inland on the peninsula to visit ruins, but never Typhoid, nor Malaria just for Coz.
I don't personally do malaria prophylaxis on the island other than using mosquito repellent and sleeping in air-conditioned rooms, although that does officially count as "malaria prophylaxis."
Ounce of prevention > pound of cure.