Interesting
From one of my textbooks, Public Health - What It Is and How It Works, by Bernard J. Turnock, Copyright 2009 (emphasis added):
"The CDC also was criticized because of the 1976 effort to vaccinate the U.S. population against swine flu, the infamous killer of 1918-1919. When some vaccinees developed Guillain-Barre syndrome, the campaign was stopped immediately; the epidemic never occurred."