In April 1955 more than 200,000 children in five Western and mid-Western USA states received a polio vaccine in which the process of inactivating the live virus proved to be defective. Within days there were reports of paralysis and within a month the first mass vaccination programme against polio had to be abandoned. The vaccine, manufactured by the California-based family firm of Cutter Laboratories, had caused 40,000 cases of polio, leaving 200 children with varying degrees of paralysis and killing 10. Paul Offit ... sets the 'Cutter incident' in the context of the struggle of medical science against polio. He profiles leading figures, notably Jonas Salk and Albert Sabin. Reviewing failures in the manufacturing and inspection processes, he exonerates Salk from blame and concludes that `the federal government, through its vaccine regulatory agency... was in the best position to avoid the Cutter tragedy'. As Offit observes, 'ironically, the Cutter incident - by creating the perception among scientists and the public that Salk's vaccine was dangerous - led in part to the development of a polio vaccine that was more dangerous'. [A] court ruling that Cutter was liable to pay compensation to those damaged by its polio vaccine ... opened the floodgates to a wave of litigation. As a result, 'vaccines were among the first medical products almost eliminated by lawsuits'. The National Vaccine Injury Compensation Program was introduced in 1986 to protect vaccine manufacturers from litigation.