Polio Infection Rates in Idaho

Poliomyelitis is a disease that came across the United States with shock in the mid-1900s. It affected all major cities in the United States, but also hit states with small populations like Idaho. Idaho’s first recorded poliomyelitis epidemic was in 1947, when 371 cases were reported according to medical researcher Carl M. Eklund. More cases were reported in 1949 with 510 cases, and 253 in 1952. This led to a panic in Idaho and a cure was the next step eliminating this disease. Historian David Oshinsky states, “never before, it appeared, had the nation been as captivated by the pursuit of a medical or scientific objective.” Parents started to panic for their children who might be affected more than the rest of the population, and children had the most cases in Idaho.

The first approved vaccinations came to Idaho in 1955 as Jonas Salk's killed-virus vaccine. Killed vaccinations carried enough antibodies in the vaccination for the body to attack it and memorize the sequence and yet not harm the host. A live vaccination is prepared from live microorganism that have been attenuated, but they still carry the code the host body needs to memorize and kill the disease. However, this live vaccination did not bode well for Idahoans. As stated by Eklund in his article, “In 12 of 17 children with paralytic disease, the first evidence of paralysis was seen in the inoculated arm.” This was terrifying for the parents but how it spread scared researchers, instead of the usual infection starting in the intestines and moving its way up to the central nervous system, the children in Idaho who were vaccinated somehow skipped the intestines and the disease went straight to the brain. This led to observations that suggested that there was live non-attenuated viruses present in the vaccines they used. This led to an increase in cases in Idaho in 1955. Eklund explains “167 cases were associated with the use of these two lots of vaccine” from the Cutter Labs.

Manley Shaw wrote a news article about a study that was done around 1956. Of the 32,000 children who received the tainted vaccination a total of 425 children aged from 7 to 12 years, who did not report to the health department, were tested to see how they reacted towards the vaccination. Of the 425 children, 139 (32.7%) reported of having some illness related to poliomyelitis within the first 25 days. Over thirty percent complained of muscle weakness as compared to about seventeen percent having no symptoms. This shows only 425 of the 32,000 children who received this vaccination, received some kind of illness or discomfort with only 16% of those having no issues. This research would confirm of all the 32,000 vaccination many were more likely affected, making the data of cases in Idaho more difficult to track.

There were cases according to Eklund's 1958 report that were not affected by the vaccinations but were infected by other means. Throughout all of 1955, data was collected to see if there was a pattern between the cases. Some researchers say these individuals who contacted polio got it from their vaccinated children but the probability was low since they had symptoms long after their children were vaccinated. Eklund did state how he was surprised that the number of cases did not give rise to a more severe epidemic, especially to how many people who were not vaccinated at that time.

In the image above is a table informing how poliomyelitis occurred in 86 people in 1955, who were in contact with a vaccinated child from the tainted batch. However, there was little evidence to support that these cases were involved with the children who were vaccinated. Researchers speculate living conditions and weather had a major impact on these 86 who were infected in 1955.

The number of cases jumped when the first vaccination was attempted. Cases sprang up from the resulting vaccinations. More cases evolved in time but were scattered. As stated above, if over half of children reported being ill, the number of cases would be much higher than reported. This disease was scary and it could spread from person to person.

Samantha Phillips, June 2021

Bibliography

Eklund, Carl M., et al. "Poliomyelitis in Idaho after Use of Live Virus Vaccine." Public Health Reports 73, no. 7 (July 1958): 637-647.

Oskinsky, David. "Miracle Workers." American Heritage 59, no. 4 (Winter 2010): 85-87.

Shaw, Manley B. "Clinical Study of Four Hundred Twenty-Five Idaho Poliomyelitis Vaccine Recipients in 1955." A.M.A. Journal of Diseases of Children 96, no. 1 (July 1958): 58-63.