Saturday, September 5, 2015

2015: 60th Anniversary of the Polio Vaccine

Even though measures of eradicating the disease in remote regions of the world still manage to gain headline news status, did you know that the polio vaccine in already 60 years old this 2015? 

By: Ringo Bones 

Back in April 12, 1955, the Salk Polio Vaccine was declared to be safe for public use after years of Dr. Jonas Salk’s dedicated lab-work to eradicate one of mankind’s greatest public health scourges. The still evolving role medical researchers – from cloistered academic eccentric to popular hero – is in many ways reflected in the history of poliomyelitis research which reached a dramatic climax with the acclaim lavished on Dr. Jonas Salk for the introduction of an effective polio vaccine in 1955. But before Salk, researchers in half a dozen countries had paved the way for polio prevention. By the first decade of the 20th Century, it was known that polio was infectious, was transmitted by personal contact and did not always result in paralysis.
However, the cause of polio had been thought to be bacteria. Then in 1909 – Dr. Sam Flexner, an American pathologist, finally isolated the agent responsible: a virus so small it could pass through the finest filters then in use at the time. But the virus had not yet been found in the bloodstream of its victims. It was assumed that the polio virus grew only in nerve cells and at the time a prototype vaccine made from infected nerve tissue produced side effects sometimes as crippling as the disease itself. Given the extremely small size of the polio virus, even light rays were deemed “too coarse” to see it and thus necessitates the use of electron microscopy which a working one wasn’t invented until 1935. And it wasn’t until 1953 that for the first time an electron microscope allowed human medical lab workers to “see” the polio virus after magnifying it 77,000 times with a stream of electrons – which at the time the most powerful electron microscopes still had trouble seeing objects tinier than 2 angstroms in diameter. 

Forty years after Dr. Flexner’s findings, a team of American scientists was able, for the first time, to grow polio viruses in non-nerve tissue after extensive lab work back in 1949. Other researchers had shown that there were three distinct types of polio viruses which produced identical symptoms and aftereffects. These viruses proliferate in the lower intestinal tract and the throat, causing symptoms so mild that they are often overlooked. Occasionally, however, they enter the bloodstream and eventually attach themselves to nerve cells, resulting in the dreaded paralytic polio. These discoveries provided the theoretical basis for the vaccines for they proved that the disease’s path allows for the production of antibodies that intercept the viruses before they reach the vital nervous system, where they do their damage. 

The first type of polio vaccine which was declared safe for widespread public use was developed by Dr. Jonas Salk and his lab associates at the University of Pittsburg using polio viruses killed by formaldehyde which sets up a protective antibody barrier against polio in the bloodstream. A few years later, Dr. Albert Sabin of Cincinnati developed the first live polio vaccine to be put into regular use and it was licensed for use in the United States back in 1962. Dr. Sabin’s polio vaccine variant generates immunity in both the bloodstream and intestinal track. And widespread global polio vaccination programs soon followed suit where as far back as 1958 a live polio vaccine variant developed by Dr. Hilary Koprowski of The Wistar Institute of Philadelphia which was applied as a mouth spray was used to vaccinate more than 250,000 Congolese citizens. 

It was only in the post-9/11 world that mass polio vaccination efforts became dangerous to the lives volunteer doctors working for charitable organizations after various Islamist Terror organizations around the world started to spread the rumor that the free vaccines used by charitable organizations cause sterility and mental retardation – thus hampering the global eradication of paralytic polio as one of the UN’s Millennium Development Goals. Even as recently as 2003, influential Islamist leaning politicians managed to ban free mass polio vaccinations just by citing the conspiracy theorists’ claims as evidence. It wasn’t only last year that mass free polio vaccinations resumed in the most deprived regions of Nigeria when the Emir of Kano recently took an oral polio vaccine in front of his subjects to show reassurance that polio vaccines are perfectly safe despite of the flimsy claims of conspiracy theorists and Nigeria’s Islamist leaning politicians. Despite its proven safety record for 60 years – conspiracy theorists and even right-wing militant Evangelical Christians in the United States are refusing to have their children vaccinated against polio. 

No comments: