The Polio Vaccine Caused More Polio Than It Prevented (Cutter Incident)

This myth contains a kernel of historical truth weaponized into a false conclusion. In 1955, shortly after Salk's inactivated polio vaccine was approved, Cutter Laboratories produced contaminated batches containing live, infectious poliovirus instead of properly inactivated virus. This 'Cutter Incident' infected 40,000 people and caused 10 cases of vaccine-associated polio paralysis. It was a genuine tragedy and a legitimate regulatory failure. However, the incident did not demonstrate that polio vaccines cause more disease than they prevent, quite the opposite. The incident occurred during a year when 28,985 polio cases occurred in the US, and vaccine efforts were preventing thousands more infections. After the incident, regulatory oversight was tightened, quality control became rigorous, and the vaccine remained effective at preventing disease. In the next five years, polio cases dropped from ~40,000 annually to hundreds, then to nearly zero. The incident is now misused as a general anti-vaccine argument, but it actually demonstrates that vaccine safety systems work: when a problem was discovered, it was fixed, and the program continued with improved oversight. Polio is a cautionary tale about manufacturing standards, not an indictment of vaccination itself.