When I was a child, back in the 1960's and 1970's every student was required to have vaccinations in order to enroll in public school. It used to be that every person who signed up for military service was required to be vaccinated. It was mandatory. Requiring vaccinations to insure good public health is nothing new. The only thing that is new are the diseases we are now facing.

Climate change will bring new diseases to the U.S. as diseases which used to be found in the tropics will be headed both further north and south. Also, warmer temperatures may facilitate a stronger likelihood of bacteria a viruses to mutate. The world population is so large now it is like a fertile petrie dish ready to spawn the growth of new diseases and because of how easy world travel is, no new diseases will be easily contained. So, the only immediate answer is to take advantage of vaccines when available.