by Tony Gould
London, England Author of A Summer Plague: Polio and Its Survivors
Poliomyelitis has been around since antiquity. An Egyptian wall-plaque from the period 1580-1350 BC depicts a young man with a withered leg, leaning on a staff. The term poliomyelitis derives from two Greek words, polios, meaning grey, and myelos, or matter, and refers to the grey matter of the spinal cord. The disease has had many names, including infantile paralysis, Heine-Medin disease, myelitis of the anterior horns, and paralysis of the morning.
The first attempt at a clinical description appeared in the second edition of Michael Underwood's Diseases of Children (1789), which attributed polio to "teething and foul bowels." The first reported outbreak was of four cases in Worksop, England, in 1835, and the first systematic investigation of poliomyelitis was written in Germany in 1840 by the aforementioned Jacob von Heine.
A puzzling aspect of polio was its transformation at the end of the 19th and beginning of the 20th century from a comparatively rare endemic disease into an epidemic disease in the world's most advanced societies, particularly in Scandinavia and the United States. Epidemics in Stockholm in 1887, in Vermont in 1894, and in Sweden again in 1905 and 1911 prefigured the great New York epidemic of 1916, in which 27,000 people, mainly but by no means exclusively children, were disabled and 6,000 died. Public health authorities responded by placarding houses where it had struck and by tearing children suspected of having polio from their mothers' arms to remove them to hospitals.
In 1905, Dr. Ivar Wickman of Stockholm recognized the contagious nature of polio and the importance of abortive nonparalytic cases in spreading the disease. In Vienna in 1908, Dr. Karl Landsteiner and Dr. Erwin Popper discovered that the infectious agent was a virus; but this filterable virus was so small that it could not be seen until the electron microscope was invented in the 1930s. In the United States, Dr. Simon Flexner succeeded in transferring poliovirus from monkey to monkey artificially, but failed to distinguish between experimental poliomyelitis in the monkey and the natural spread of the disease in man. As a result of his influence, the discovery that polio was initially an intestinal infection, the virus circulating by the oral-fecal route, was delayed in America. It was thought that the virus was air-borne, and in the 1930s, time and money were wasted in developing ineffective nasal sprays.
A United States Army virus commission operating in North Africa during World War II was mystified by the number of young servicemen contracting polio in an area thought to be free of it. Subsequent investigations revealed that there was polio, but it was never recognized in the acute phase. In countries where polio was endemic, they reasoned, there were not more cases because most people acquired immunity in infancy by having a mild form of the disease. In countries where developments in hygiene and sanitation had reduced the occurrence of contagious diseases, by contrast, people no longer acquired immunity naturally in infancy and became vulnerable to the virus when it circulated: hence the periodic epidemics. In other words, epidemic polio was a byproduct of the measures taken to control other infectious diseases.
The search for a vaccine was facilitated by Franklin Delano Roosevelt, four times President of the United States. Having contracted the disease at the advanced age of 39 in 1921, his personal quest for mobility led him to transform an old spa at Warm Springs, Georgia, into a hydrotherapy center for polio survivors. As his fame and influence grew, so did the organization he had founded: the Warm Springs Foundation expanded into the National Foundation for Infantile Paralysis (March of Dimes), focusing on development of a vaccine as well as treatment. By the time of FDR's death in 1945, The National Foundation, under the direction of his friend and sometime legal partner, Basil O'Connor, was an immensely powerful voluntary health organization, funding most significant research into polio in the United States.
The discovery by John Enders and his team of Harvard scientists in 1948 that poliovirus could be cultivated in non-nervous tissue led to a Nobel Prize for the trio and opened the way to the manufacture of a polio vaccine. Jonas E. Salk was the first to take advantage of this breakthrough. Salk's formalin-inactived poliovirus vaccine (IPV) was subjected to the most extensive trial in the history of medicine before it was pronounced "safe, potent, and effective" on the tenth anniversary of FDR's death on April 12, 1955.
Albert B. Sabin's live, attenuated oral poliovirus vaccine (OPV) was never tested in that way but was used successfully and on a massive scale in the Soviet Union and eastern Europe in the late 1950s before ousting Salk's IPV as the vaccine of choice in the United States in the early 1960s. The great advantage of OPV was twofold: it was taken orally rather than injected; and by following the oral-fecal route it could provide "herd immunity" (immunity to non-vaccinated people living nearby), not merely individual protection. Arguments over the relative merits of the two vaccines have outlived their developers and continue to this day.
The decade between the end of World War II and the licensing of the Salk vaccine saw ever larger and more frequent waves of epidemics in North America and Europe, characterized by a rise in the average age of those who contracted the disease. Polio could no longer be called infantile paralysis. Improvements in the medical management of acute poliomyelitis, inspired by Sister Kenny and others, meant a higher survival rate among the more severely disabled, particularly those who depended on ventilators for survival. In the 1950s, the March of Dimes established and funded 16 regional respiratory centers around the United States.
The vaccines effected a dramatic decline in polio after the mid-1950s, and by the end of the decade the March of Dimes was looking for a new cause to support. Between them, IPV and OPV have eradicated the poliovirus from most parts of the world, and after recent initiatives in China and the Indian subcontinent, few places remain inaccessible to the vaccination campaigns mounted by the World Health Organization, Rotary International, and other governmental and non-governmental agencies in their quest to eliminate the disease worldwide by the beginning of the 21st century.
The conquest of polio left survivors of the earlier and highly publicized epidemics of the 1950s stranded like veterans of some forgotten war. The confirmation of post-polio syndrome and the various late effects of polio in the 1980s has to some extent re-awakened interest in a disease which was unique in the sense that – in the words of the medical writer John Rowan Wilson – “its rise and fall took place within a single lifetime.”