We live in Mexico in the winter. Have been doing this for over 30 years. have never been asked for proof of vaccination. This is entering by land. Air is different. Mexico is one of the few counties that do not even check your ID. It is illegal but by land you can just drive past the place where you get a tourist pass!! There are cameras but half the time they do not work. When you go into the booth to get a tourist pass and then your vehicle permit they could care less about your vax status. How ever being vaxed is a good idea. Presently Mexico is having outbreaks of Flu, respiratory illness and Covid. If you are on tours wear a mask. Crowds are horrible.