I am grateful that Smallpox has been eradicated world wide and Yellow Fever and Polio in the US. I have a large vaccination scar on my arm from the Smallpox vaccine they gave me as a baby. I was one of the last to be vaccinated and a lot of people older than me did not need it but I was born in a major city with lots of international traffic and they were still vaccinating for it there at the time I was born. I used to tell kids when they were 'spreading cooties' that it was my cootie vaccination and that I was immune to them (I always hated that game and never understood the boys vs. girls thing). Also, it probably doesn't surprise you that I wasn't exactly surrounded by friends.
I'm reading Fever Season by Jeanette Keith about the 1878 yellow fever epidemic in Memphis that infected so many and resulted in so many deaths. I had a yellow fever shot before going to Panama when I was young and if there is one vaccination that I will always remember, this is the one. It was a miserable shot that makes any after affects of other shots pale in comparison and the disease itself it far, far worse. Locally, we get paranoid about the mosquitoes around us carrying West Nile Flu and I have to say that I'm so glad that we don't have to worry about them carrying Yellow Fever to give to our friends and family.
I pray that we the bird flu virus never mutates to be communicable between humans because it has a 60 percent mortality rate and I can't imagine a pandemic that is so fatal.