Smallpox used to kill millions of people - Estimates are that 300 million to 500 milion people died of smallpox in the 20th century. The World Health Organization estimated that as many as 15 million people contracted smallpox in1967, and 2 million of them died in 1967. In December 1979 Smallpox was verified as eradicated from the globe by the World Health Organisation, by vaccination, as there are no non-human hosts for Smallpox virus. No one is vaccinated for smallpox anymore anywhere because smallpox no longer occurs.
In 2011 rinderpest was announced to no longer be present on Earth due to vaccination by the United Nations Food and Agriculture Organisation. The human measles virus is thought to have emerged from rinderpest virus between 1000 and 1100 AD
The complete elimination of small pox and rinderpest are true miracles - million and millions of lives and dollars saved, every year, on into eternity.
Most of modern medicine is concerned with helping one person at a time recover from illness or disease. Vaccination allows whole populations of humans to never fall ill to an illness, that might indeed be disabling or even fatal to some of the population.
Some vaccinations do carry some risk and are only suggested by the medical community to folks known to be at serious risk - rabies comes to mind. There is NO CURE for rabies in humans, but humans vaccinated for rabies in a timely manner almost always survive without complications, as opposed to dying a horrible death AND exposing all of their health care personelle with the risk of exposure to rabies.