1955 Approval and Release of the Salk Vaccine

Poliomyelitis, commonly known as polio, is a disease that terrified parents through much of the 20^th century. Polio tended to make its presence known during the warm summer months, paralyzing thousands of children every year. The transmission process of poliomyelitis was unknown until the 1940s, adding to the uncertainty and fear associated with this disease. Historian Karen L. Wellner discusses in her article that “many public libraries, water fountains, swimming pools, and movie theaters were shut down during the summer months.” It was also encouraged to leave kids at home while parents went grocery shopping to decrease risk of exposure, and afternoon naps were implemented to help decrease the amount of stress in young children. [vii]

Poliomyelitis could affect anyone, but it seemed to greatly impact young children and babies. Volney Steele identifies the symptoms of polio as “fever, sore throat, headache, vomiting, stiffness and muscle rigidity of the neck and back, and paralysis…half of patients affected by paralysis eventually regained normal muscle function” [vi]. Polio received the name infantile paralysis due to paralysis being one of the symptoms it manifested in children, which again added to the fear parents were understandably experiencing during this time. In the article “The Biggest Public Health Experiment Ever” the authors touch on the fear parents in Montana were experiencing at this time by stating that even though cancer had a higher death rate among children the uncertainty of polio and how “it struck without warning, killing some victims and leaving others in iron lungs, with deformed limbs, or needing leg braces to stand or walk” added to the fear associated with polio and the desire to manufacture a polio vaccine [ii].

The first polio vaccine was manufactured by Dr. Jonas Salk who “favored using a killed virus for polio vaccine production” [ii]. Dr. Salk and his team worked on the polio vaccine from 1947-1952 during which they aimed to identify the number of poliovirus strands. Vaccines were originally tested on monkeys and at the end of 1951 Dr. Salk and his team were given permission to start human vaccination trials from National Foundation for Infantile Paralysis [vii]. The first Salk poliomyelitis vaccine trial was administered beginning April 26, 1954, with six-year-old Randy Kerr in Virginia being the first ever recipient. The number of Salk poliomyelitis vaccine trial recipients would rise over more than two million within the coming weeks becoming “the largest public health experiment in America” [iv]. The first trial was a success and the Salk vaccine was considered safe and effective, but the vaccine safety profile came into question in April of 1955. The Salk vaccine program started on April 19, 1955 and was ceased on the 27^th due to two cases of poliomyelitis being report following days after vaccine administration, and it was concluded that the virus was not properly deactivated during the manufacturing process. In the article “Vaccination-Induced Poliomyelitis in Idaho” medical researchers report that “within 26 days after the beginning of vaccination, 20 vaccinated children had developed clinical poliomyelitis…three of these children died…11 showed paralysis in the arm of injection.” [v]. Many epidemiologists associated with the Cutter Lab kept in close contact with local and state health officers to monitor the number of polio cases following vaccine administration.

The Communicable Disease Center (CDC) and NIH conducted a national investigation that linked the vaccine-associated polio cases to the vaccine produced in Cutter Laboratories. All vaccine distribution by this lab were ceased until further investigation and safety testing were concluded. It was on May 14, that the Surgeon General announced that the vaccines were cleared to resume and assured that procedures would be implemented to guarantee the safety of the public. All states and territories were required to report on a weekly basis the number of poliomyelitis cases among vaccinated children. One epidemiologist concluded in 1956 that “there is no evidence that use of vaccine has caused poliomyelitis since the adoption of the new safety standards.” [i]. On December 8, 1956, the Idaho Statesman reported that 256,082 Salk vaccines had been distributed in Idaho since the previous spring. Upon research it was determined that some effectiveness was gained following the first dose but that 3 doses within a 5-week period was advised to achieve the full effectiveness [iii].

Laura Sandoval, June 2021