Vaccines are a dead or neutralized virus and bacteria that are introduced into a person`s body to prevent or immunize a person or animal from a certain disease.
With the evolution of medicine and scientific research, in a few years (probably 50 years) there will already be vaccines for incurable diseases, and countries that are now considered developing or undeveloped countries will become safer and with fewer diseases, perhaps not even. There will be more diseases in a few centuries.