Jonas Salk And The Rest Of The Story On The Polio Vaccine

Today marks the 100th birthday of Jonas Salk, the American scientist who is chiefly responsible for creating the first polio vaccine distributed for use. Salk was of Russian-Jewish descent and was born in New York City. Jonas’s parents encouraged his academic pursuits and he graduated high school at the age of fifteen. After changing his career path from law to medicine, Jonas was accepted into New York University School of Medicine at the age of 19. Salk’s interests were chiefly in research instead of clinical practice, so following his internship Salk accepted a research position at the University of Michigan in Ann Arbor. Jonas spent several years there developing influenza vaccines using inactivated viruses instead of the attenuated or weakened viruses that were the standard of the time. Attenuated viruses were capable of being pathogenic while inactivated viruses would theoretically stimulate an immune response without the risk of contracting the disease.

Jonas Salk went on to establish a Virus Research Laboratory in Pittsburgh, Pennsylvania. Salk spent several years studying the poliovirus and developing methods of mass producing “killed-virus” vaccines similar to his work with influenza, using monkey kidney cells. Jonas built upon the work of other researchers such as Dr. Hilary Koprowski, whose work showed that polio could potentially be prevented with a vaccine. After culturing the virus, he inactivated it using formaldehyde. Salk’s initial field trials in monkeys and previously infected children seemed to indicate success was on the horizon.

With the possible end of polio in sight, clinical trials were rushed. Typical trials take years to completely document efficacy rates and safety data. This trial lasted less than a year. Salk’s vaccines were administered by June 1954, and approval was voted on in April 1955. Manufacture of the vaccine began the next day.

Almost as soon as mass inoculations began, the first child was diagnosed with polio. The numbers quickly climbed. As paralysis began in the arms that received the injections, the cause was attributed to Jonas Salk’s vaccine. Sadly, this wasn’t surprising to many researchers who had seen the careful safety testing protocols being disregarded in the rush to produce the vaccine ahead of the coming spring, and its influx of polio cases.

“We had eighteen monkeys. We inoculated them with each vaccine that came in. And we started getting paralyzed monkeys. They just went ahead and released the vaccine anyway, a lot of it. The monkeys, they just discarded.”

Dr. Bernice Eddy, an NIH staff microbiologist, reported her findings to her superiors. The defective lots of vaccine that were causing the polio infection came from Cutter Laboratories, one of the few pharmaceutical manufacturers selected to produce the vaccines.

Another scientist who actually visited the Cutter facilities, Julius Youngner, reported appalling conditions at the factory directly to Jonas Salk. He passed on his fears that the production facility was having serious problems adhering to the procedures required to achieve proper inactivation. Salk promised to follow up on the issues raised but shortly after, the infamous Cutter incident became common knowledge, indicating that Salk had not in fact addressed the concerns had been raised and that a catastrophe had occurred.

The push to produce this promised miraculous vaccine led to one of the worst pharmaceutical disasters in history. Several Swedish researchers, on a parallel path to developing a polio vaccine, heavily criticized Salk’s inactivation methods and his choice of polio strains to include in the vaccine. These fears were horrifically realized when Cutter Laboratories distributed several batches of the vaccine that were contaminated with live polio virus. The first reports of infection came a mere two weeks into the national vaccination campaign. At the end, ten people were dead and 164 were permanently paralyzed from the vaccine or the ensuing infections that were caused by it.

Safer vaccines against the poliovirus came in the years that followed, but too often the horrors of the research into the initial one, and the valuable lessons it taught about safety, are forgotten or not reported.