During the mid-twentieth century, cases of polio were rampant throughout much of the world. Hundreds of thousands of people worldwide were affected by the disease, which primarily afflicts children. In the United States, where Salk was based, an epidemic in 1952 had killed over 3000 people and left more than 21,000 paralysed.
At that time, polio was one of the western world’s greatest fears. It was easily spread, very common, and completely un-preventable. By the 1950’s, the race was well and truly on to find a vaccine, but success had been limited. Potential drugs had been trialled in the past, but none had produced immunity, and one had even been blamed for cases of paralysis and one death.
Salk’s vaccine, which used killed virus rather than the live strain, was the first drug to have any considerable positive impact. In 1953, Salk announced that his injected polio vaccine had proved successful in a small trial group of patients, but it needed more testing. Over the next two years, a huge campaign was launched to trial the drug. Almost 2 million schoolchildren took part, aided by tens of thousands of physicians, public health officers, school workers and volunteers.
On April 12th 1955, the announcement finally came: the vaccine was a clear success. Jonas Salk became an overnight celebrity. His name was painted in shop windows; he received medals, honorary degrees, and even the offer of a ticker tape parade. Approached by journalists over the question of who owned the vaccine patent, Salk famously replied: “There is no patent. Could you patent the sun?”
Salk’s ingenuity helped to wipe out polio in the west. The Americas were declared free of the disease in 1994, with Europe following suite in 2002. That’s not to say that polio is no longer an issue. The disease is still endemic in Pakistan, Nigeria and Afghanistan, and difficulties in administering immunisation programmes still hamper efforts to wipe out the disease entirely in parts of South Asia and Africa. However, cases have come down from the hundreds of thousands to the hundreds, and there’s no doubt that countless lives have been saved by Salk’s vaccine.
Today, work continues to develop new preventative medicine for polio. Salk’s vaccine uses killed virus, but there would be considerable advantages to developing a polio vaccine that didn’t use any of the virus, dead or alive. There’s a strong possibility that, with a synthetic vaccine, scientists could finally wipe out polio once and for all. By providing intensely bright light, synchrotrons like Diamond allow scientists to determine the atomic structure of diseases like polio, and design drugs based on this understanding. In this way, Diamond and other synchrotrons are playing an important role in helping with the development of next-generation vaccines.
The polio vaccine created by Jonas Salk is one the most medically and culturally-significant breakthroughs of the twentieth century. Indeed, Salk’s work was of such importance that Google has today seen fit to immortalise him in their Google Doodle. The image shows children laughing and playing, a pair of them holding up a sign that reads “Thank You Dr Salk!”: a fitting recognition for a man who’s work continues to save many children’s’ lives the world over.