One of the diseases that spreads the fastest is measles. One of the diseases that infects the most number of people is flu, every year 3-5 million people get sick from flu.
I’m going to say yes, I think one day (probably many years away) there will be a vaccination or a cure for almost all cancer. This might sound difficult to believe, but science and technology move really fast. 50 years ago the best computers in the world were basically just like giant pocket calculators and now we all have smart phones, so it’s difficult to predict what technology we’ll have in 50 or 100 years time. We’re get better at treating cancer each year so I think that one day we will have a vaccine / cure for most cancer.