When touting the merits of vaccination, public health officials often brag about the campaign to eradicate polio. What they rarely if ever disclose, however, is that both the inactivated polio vaccine (IPV) developed by Jonas Salk and the live-virus oral polio vaccine (OPV)—developed first by Polish scientist Hilary Koprowski and later by Albert Sabin—frequently have caused the very condition they were supposed to prevent.[pullquote] Despite Salk’s belief that a ‘killed-virus’ vaccine could not accidentally cause polio in those inoculated, the number of reported polio cases rose immediately and dramatically within a year, with particularly steep increases in some states—including a 642% spike in Massachusetts.