What is it?
Polio (polyomyelitis) is a highly contagious disease caused by the poliovirus. While most cases are asymptomatic, when the poliovirus migrates from the gastrointestinal tract to the central nervous system, paralytic polio can occur. When this happens, victims can no longer move parts of their body and may become confined to living with an iron lung to allow them to breathe better if they can no longer breathe normally. This was the case in the first half of the 1900’s when polio reached pandemic proportions in areas across the world (Trevelyan, B., 2005).
Polio is spread in a gross way, by fecal (meaning poo) oral (meaning mouth). Ironically, poor sanitation in pre-modern times made it so that polio spread more and thus a natural immunity existed that protected the population from severe cases. So once society became more sanitary by implementing sewage systems and clean water supplies, natural immunity declined, giving rise to more severe cases. This lead to a rapid movement globally to fight it in the 1950s (Trevelyan, B., 2005).
How did we fight it?
Since polio was endemic so most people caught it throughout most of its history, we did not really fight it and did not have many treatments. Once polio began to become more of a concern in the early 1900s, a mad dash occurred to come up with treatments, most being ineffective. One remedy included electrifying the lower legs to allow oxygen to flow more freely, giving baths in almond meal, rubbing mustard or some other random substance on the individual, and having the afflicted drink radioactive radium water, among other ineffective liquids. Of course, these had no affect and even hastened death in some cases (Gould, T. 1995).
While most therapies explored in these times proved ineffective, some effective measures were discovered. These included the iron lung to aid with breathing, a treatment regimen, and an anti-polio antibody serum (Hammon, W., 1955). With the serum, William Hammon in 1950 was able to isolate a liquid with antibodies against the poliovirus from the blood of polio survivors. However, the most effective treatment was preventative in the form of a vaccine!
Vaccines
In the early 1950s, John Enders and his research group were able to grow poliovirus in human tissue, which lead to the development of the polio vaccines, winning the Nobel prize in 1954. The first polio vaccine was developed by Jonas Salk in 1955. The vaccine (called inactivated poliovirus vaccine, or IPV) was made up of killed poliovirus so that the immune systems of those treated with the vaccine would be able to recognize what the virus looked like without actually having to become injected, thus providing defence against it. A second type of vaccine was created by Albert Sabin, the oral polio vaccine (OPV), and unlike the first vaccine, it contained live but weakened forms of the virus. The oral vaccine has the advantage of being easily taken as all one has to do is get it sprayed in the mouth, and so it is commonly used in children. Upon these vaccines being rolled out in the United States, the annual number of polio cases decreased from a peak of 58,000 cases to just 5,600 in 1957 (Sass, E., et al. 1996).
Since then, there has been a massive effort to eradicate polio and it could likely become the second human disease behind smallpox to become extinct in the near future. The eradication campaign began in 1988 by the World Health Organization (WHO), Rotary International, the CDC, and UNICEF through the Global Polio Eradication Initiative (GPEI). In 1980, there was an estimated 400,000 polio cases; 2022 saw just 30 cases in the wild (Global Wild Poliovirus 2017-2023, 2023). According to the WHO, 2023 is the target year to interrupt the transmission of polio with eradication officially occurring in the coming years . Let’s hope this awful disease is done for once and for all in the near future!
References
Hammon, W. (1955). “Passive immunization against poliomyelitis”. Monogr Ser World Health Organ. 26: 357–70. PMID 14374581
“Global Wild Poliovirus 2017 ‐ 2023” (PDF). GPEI. 20 June 2023. Archived (PDF) from the original on 23 June 2023. Retrieved 23 June 2023.
Gould, T. (1995). A summer plague: polio and its survivors. New Haven, Conn: Yale University Press. p. 23. ISBN 0-300-06292-3.
Sass, E., Gottfried, G., Sorem, A., eds. (1996). Polio’s Legacy: an oral history. Washington, D.C: University Press of America. ISBN 0-7618-0144-8. Archived from the original on 2007-04-03. Retrieved 2007-05-08.
Trevelyan, B., Smallman-Raynor, M., & Cliff, A. D. (2005). The Spatial Dynamics of Poliomyelitis in the United States: From Epidemic Emergence to Vaccine-Induced Retreat, 1910-1971. Annals of the Association of American Geographers. Association of American Geographers, 95(2), 269–293. https://doi.org/10.1111/j.1467-8306.2005.00460.x