In 1976, the U.S. swine flu vaccinations were halted in nine states after three elderly people in the Pittsburgh area suffered heart attacks and died within hours of getting the shot. On 16 Dec, increasingly concerned about reports of the vaccine touching off neurological problems, especially the rare Guillain-Barre syndrome, the U.S. government suspended the program. The nationwide vaccination effort began as a result of a novel virus that was first identified at Fort Dix, N.J., and labeled a “killer flu.” Experts compared it to the Spanish flu of 1918 and sounded the alarm of a possible major pandemic. In fact, the virus never moved outside the Fort Dix area. Later research showed it would probably have been much less deadly than the Spanish flu.