Cutter's polio vaccine contained live virus — 120,000 children exposed, 10 died

In April 1955, Jonas Salk's polio vaccine had just been declared safe and effective. Cutter Laboratories, a family-owned pharmaceutical company in Berkeley, California, was one of several licensed manufacturers. The company produced batches of the vaccine that, despite passing the required safety tests, still contained live polio virus. The vaccine was shipped and administered to children across the western United States before the problem was discovered.

An estimated 120,000 children were exposed to live polio virus through the Cutter vaccine. Of those vaccinated, 40,000 developed abortive poliomyelitis, 56 developed paralytic polio, and 5 died. The outbreak spread to family members and communities, causing an additional 113 cases of paralysis and 5 more deaths. The vaccine was withdrawn on 27 April 1955, but the damage was done — the epidemic had already moved faster than the recall.

A congressional investigation found that the NIH's Laboratory of Biologics Control had failed to provide adequate oversight. The director of the NIH, the director of the microbiology institute, and the Secretary of Health, Education, and Welfare all resigned. In the landmark Gottsdanker v. Cutter Laboratories case, the court found Cutter not negligent but liable for breach of implied warranty — a precedent that shaped product liability law. Cutter survived the disaster, grew its business, and was acquired by Bayer in 1974.