This chart is why vaccines matter. It compares declines from the number of cases of communicable diseases during an average year in the 20th century, to cases reported in 2010. And for diseases that we've fully vaccinated against — things like smallpox, which used to infect nearly 30,000 people each year — the decline is 100 percent.
Add all these up, subtract the cases that still exist, and you come out to just shy of 1 million cases of disease prevented annually.
Vaccines are incredible: they reduced the number of cases of Rubella from 47,745 to six, more than 99 percent. Its now a disease so old and uncommon that, even though we get vaccinated for it, most of us don't really know what it is (its a bit like measles, but also different.) Vaccines are the sole reason there have been 100 percent declines in diseases that used to effect tens or hundreds of thousands of Americans.
A lack of vaccines matters, too. Measles hit a 20-year high this summer, with 280 cases recorded. Ninety percent of those cases were among the unvaccinated. When vaccines fall, its easier for a disease to make a comeback. Vaccines matter, a fact thats probably most sharply underscored when people stop getting them.