pharmaceutical companies. he heads pfizer's vaccine operation. >> people haven't seen these diseases in a while, so people become complacent. they don't vaccinate. and what they wind up doing is putting their children and themselves in considerable risk of a severe disease and infection. polio, even though people aren't worried about it because they haven't seen much of it, is still present in many parts of the world, and it can easily be introduced into a non-vaccinated population. and from what we've seen in other parts of the world, once it's introduced, it will spread very rapidly and cause a lot of disease. >> the fear, my friends, is polio. but soon, perhaps within a year, there may be a vaccine. >> thanks for visiting with us. hey, kids, how about saying good-bye, huh? >> good-bye! >> when i was a child and the big scare was polio, where you would see your friends playing ball outside with you, baseball and basketball, and all of a sudden get sick and be in bed, be in an iron...