April 12 1955 – The Polio Vaccine is Declared Safe and Effective
*Image Credit: Wikimedia Commons In the history of mankind, few diseases have caused more damage in the lives of young children than poliomyelitis. The crippling condition, caused by a virus entering the central nervous system, finally met its match when Jonas Salk received approval for a vaccine on April 12, 1955. In the decades since, worldwide cases have been to reduced to a microscopic percentage compared to the numbers experienced in the first half of the 20th century. Polio is a highly infectious disease that, for the most part, results in no symptoms whatsoever — less than 1 per cent of cases turn into the devastating paralysis most people associate with the virus. Generally speaking, the contagion enters an individual orally, resting in the back of the throat or the intestines. Once there, the person’s immune system will usually seize on the invading organism and help the body develop a defense against it. Children, who naturally have weaker immune responses, are therefore especially susceptible to infection. Problems occur in about 1 out of every 10 instances, when the virus finds a way to slide into the bloodstream. From there, polio gains access to the brain and spinal cord, giving it the opportunity to damage tissue. Even then, the symptoms are often more along the lines of acute influenza — high fever, fatigue, a sore throat, vomiting — meaning the illness passes without arousing too much suspicion.