At the University of Rochester Medical Center, researcher John Treanor saw a wide range of reactions, from a small rash to swelling the size of a grapefruit. About 5 percent of the 170 participants had rashes that spread to other parts of the body. It took time and experience, he said, for the team to get comfortable with the natural course of the vaccine. "The reactions we are seeing are totally out of line with today's vaccine experience and absolutely in line with historical experience," said Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases. "In the 30 years since we had routine vaccination, the public's tolerance level has gone way down."
I remember nothing about my smallpox vaccine except that big ol' scab.