Poliomyeltis

Poliomyelitis, or polio is a virus that enters the body through the nose or mouth. It spreads from person to person through infected faeces. Most people who become infected do not develop any symptoms, their antibodies combatting the disease giving them life long immunity. About a tenth suffer from flu like symptoms but then recover. In approximately 1% of cases the virus damages nerve tissue causing paralysis. Children are most vulnerable to the disease, though adults can also develop polio. During the first half of the 20th century there were several polio outbreaks in the USA which caused widespread panic amongst parents.

A Vaccine

Since the 1900s there had been several attempts at developing a poloi vaccine but all had failed, mainly because it was not understood that more than one strain of the virus were causing the disease. It was later discovered that there were three main types of the poliovirus and 125 strains, so a virus would have to target all of them. Much work was funded by the March of Dimes, and organistion that was set up witht the help of President Roosevelt, who himself had contracted the paralysing form of the disease in the 1920s.

In 1937 Dr. Jonas Salk who had been researching viruses at the university of Michigan became the Head of the Virus Research Lab at the University of Pittsburg. There he bagan working on the poliovirus, sorting through its many strains. One of the main drawbacks of the study was that it was hard to develop enough of the poliovirus to study, but this problem was solved in 1949 with the devopment of cell culture by a team of researchers at Havard University. Salk then used formaldehyde to kill the virus but keep enough intact to build up the bodie's immune system.

Salk started work on refining the polio vaccine on July 2 1952 on children who'd recovered after having the disease. He went on to test the vaccine on volunteers who did not have the disease, including himelf and his family. A nationwide testing began in 1954 after Salk's findings were published in the Journal of the American Medical Association