Vaccinations
Until the 1950's, most people never got any vaccinations at all. To see how much kids' lives have changed because of vaccination, find somebody who was a kid in the 1940's or 1950's (They would be about 65 or 75 years old now - your grandparents might be about the right age). Ask them about their experiences with measles, mumps, chickenpox, and polio - all diseases that kids your age get vaccinated against now. Ask them whether they got a smallpox vaccination (you did not get one - why not?).
Main page about vaccination
To find out more about viruses, check out these books from Amazon.com or from your library:
