https://www.latimes.com/business/story/2020-05-28/coronavirus-vaccine-development-timeline(excerpt)
"The key lesson about the hazards of rushing a vaccine into production comes to us from Berkeley, where a small pharmaceutical company named Cutter Laboratories was chosen by the government in 1955 as one of five private manufacturers of the Salk polio vaccine.
The Salk vaccine incorporated a dead polio virus, potent enough in its active guise to produce a strong antibody reaction in humans but inactivated through treatment with formaldehyde so it wouldn’t cause disease.
Because of a series of manufacturing errors and poor government oversight, however, some of Cutter’s vaccine lots were contaminated with the live virus. An estimated 40,000 children contracted polio from Cutter’s vaccine. Many family members who had not been inoculated contracted the virus from their vaccinated children. About 200 victims were permanently paralyzed, and 10 died."
