History of Polio

The disease

Poliomyelitis, or more commonly known as polio, is an infectious and contagious disease caused by a virus (poliovirus) that is transmitted from person to person and through contaminated food and water.

Polio has been known since ancient times. For example, an ancient Egyptian stele from 1350 B.C. was found depicting a man who was presumably healthy but had a leg that was believed to be thinned by polio. History also tells us that the Roman emperor Claudius had a limp, probably due to polio, and that it could be the aftermath of polio. However, it was in 1789 that the first clinical description of the disease was written by the British physician Michael Underwood. It was called "Heine-Medin disease" after the publication of the first medical report on polio by Jakob Heine (1840) and the first study by Karl Oskar Medin (1890). In addition, because the epidemics affected mainly very young children, polio was
also called "infantile paralysis".

Until the end of the 19th century, polio was a disease affecting mostly children between the ages of 6 months and 4 years. The infection, when contracted early in life, usually left only mild sequelae and permanently immunized the victim against the disease.

It is ironic that improvements in urban sanitation in the 20th century have reduced the opportunity for exposure to the virus, thereby reducing the chances of naturally acquiring immunity to polio. This situation has, in fact, led many individuals to contract the disease in late childhood and even in adulthood. These victims suffered much more severe after-effects, such as motor paralysis or skeletal atrophy, which could lead to permanent deformities and disability, among other things. Until the 1950s, the percentages of paralysis and death cases increased dramatically, reaching levels of 5% of death and 37% of paralysis.

The fight against polio

Audio and video reports. CBC Archives 1955-2002. French - English.

The Radio-Canada archives site presents several audio and video clips on the ravages of polio in Canada. From the peak of the disease in the 1950's to Post-Polio Syndrome, these stories shed light on the various aspects of polio in Canada.

You can also see CBC reports in English.

Health Heritage Research Services

English. Resources about the history of polio in Canadawritten by Christopher J. Rutty, Ph.

The iron lung

The iron lung was invented at Harvard University and tested at the Boston Children's Hospital in 1928. It was inside such devices that a polio victim was placed at the worst of his infection to help him, to the best of the knowledge of that time, to get better. By controlling the air pressure inside the chamber surrounding the patient's body, the device allowed the patient's lungs to breathe when they became too weak to work on their own. Although thousands of lives were saved, it was by no means a preventive treatment or a cure for polio.

You can get a little more information about the iron lung here.

Vaccines

The first attempt to develop a polio vaccine was made by Maurice Brodie at New York University in 1935. He used virus taken from the spinal cord of monkeys to develop a powerful and effective vaccine, but his vaccine proved unable to transmit the desired immunity to humans.

In the early 1950s, a group of researchers at Boston Children's Hospital succeeded in cultivating the virus from human tissue. This led, in 1952, to the development of a vaccine by Jonas Salk of the University of Pittsburgh. The Salk vaccine, which uses an inactivated strain of the virus, was formalized in 1955. It can provide protective immunity in more than 99% of people who receive three injections against all three strains of poliovirus (PV1, PV2, PV3). Today, in Canada, it is part of the routine infant and childhood vaccines, resulting in the near eradication of this virus in North America.

In 1957, a second polio vaccine was developed by another researcher, Albert Sabin. This vaccine, licensed for use in 1961, is an active vaccine, that is, containing a live, attenuated strain of poliovirus. Sabin's vaccine is orally administered, inexpensive, effective, and easy to administer, making it more suitable for mass immunization, particularly in developing countries. However, this vaccine sometimes fails due to viral interference. Viral interference is a phenomenon in which a cell infected with a virus becomes resistant to a second emerging infection by a superinfectant virus.