The Cutter incident: On April 12, 1955 the government announced the first vaccine to protect kids against polio. Within days, labs had made thousands of lots of the vaccine. Batches made by one company, Cutter Labs, accidentally contained live polio virus and it caused an outbreak.
More than 200,000 children got the polio vaccine, but within days the government had to abandon the program. Some 40,000 children got polio, several hundred were left with paralysis, and about 10 died, said Dr. Howard Markel, a pediatrician and director of the Center for the History of Medicine at the University of Michigan.
The epidemic that never was: In 1976, scientists predicted a pandemic of a new strain of influenza called swine flu, and advisers urged President Gerald Ford to hastily prepare a vaccine.
The government launched the program in about seven months and 40 million people got vaccinated against swine flu, according to the CDC. That vaccination campaign was later linked to cases of a neurological disorder called Guillain-Barre syndrome, which can develop after an infection or, rarely, after vaccination with a live vaccine.
Rushing a vaccine could lose the public's trust: People's mistrust of the system makes the idea that the FDA would rush this process before late stage clinical trials are complete "colossally stupid," said Markel.
"All it takes is one bad side effect to basically botch a vaccine program that we desperately need against this virus. It's a prescription for disaster."