ANN ARBOR, Mich., April 20, 1955 (INS) - A brilliant scientific experiment has been completed, leading to a workable vaccine against crippling polio and making the man responsible a celebrity overnight.
How did it happen? Why did this researcher succeed where others before him had failed?
The researcher is Dr. Jonas Salk, the 40-year-old scientist who developed the polio vaccine that bears his name.
In 1953, less than two years after he became interested in the challenging problems presented by polio, he succeeded in producing a vaccine believed capable of bringing crippling polio under complete control.
One explanation of Dr. Salk's success is that he is a "good technician." The phrase carries the implication that all he did was build from someone else's "blueprint."
While Dr. Salk himself would be the last person to quarrel with this somewhat slighting description, he nevertheless was the first to develop a vaccine judged good enough to be used in medical history's greatest mass experiment.
His friends and colleagues at the University of Pittsburgh's virus research laboratory shrug off the "technician" tag. Dr. P. L. Bazely says:
"Certainly Dr. Salk built on to knowledge and experience of others. But he was the one who combined their advances with his own background.
"He was the one who had the insight and drive to organize and carry out the project."
Exactly what was the state of polio knowledge when this young and intensely determined researcher became interested in the complicated problem of an immunity-granting vaccine?
First, three main polio virus strains had been identified -- Brunhilde, Lansing and Leon.
These viruses were found in the bloodstream of polio victims. This indicated that the virus was taken in through the mouth (food, drink, air, dirty hands -- any number of ways) before making its way to the nerves, where the damage is done.
It also was generally accepted by then that every person in the world is subject sooner or later to infection by one or another of the three known types of polio virus.
In most of us, there may be no sign of the infection at all. For others it may be a passing sore throat, but for a proportionately small number of persons the infection develops into tell-tale paralysis.
The explanation - most of us get infections mild enough to throw it off. As a result we build up our antibodies -- the elements that fight disease -- until we have enough to be immune for life. But others may never be exposed to mild doses; when a strong virus dose hits them, there are not enough infection-fighting antibodies to help them.
Thanks to Dr. John F. Enders and his associates, there was a safe way to "build" large numbers of viruses. Thanks to Dr. William McD. Hammon, there was knowledge that antibodies in the blood could stop the virus.
Thanks to Drs. Howard A. Howe and Isabel Morgan, there was a technique for "killing" potent virus without ruining its ability to stimulate antibodies.
Here then was Dr. Salk's task as he set it for himself: Make a vaccine usable against all three polio types; make it good enough to stimulate sufficient antibodies and safe enough to administer without bringing on polio or "side effects."
How did he do it?
Under Dr. Salk's procedures, the way to make a suitable vaccine to protect children from polio requires first of all a large number of monkeys, which are expensive.
The vaccine "factory" system starts with the monkey, as Dr. L. James Lewis, a Salk re-arch associate, put it: "The monkey is indispensable for making polio vaccine. We will need a continuing supply of them for both testing and serum production."
The monkeys are obtained for $42 postpaid from India, Burma or the Philippines. After tests, their kidney tissue is used for the "food" upon which the polio virus feeds.
Dr. Lewis estimates one set of monkey kidneys produces enough "food" to make vaccine in sufficient quantities to immunize 500 children. Here is what happens then:
1. The kidney is ground up, chemically treated with tripsin and placed in a test tube.
2. Polio virus is placed in the tube to feed and grow at the tissue's expense. Also added is a "soup" of nutrient materials called "mixture 199."
3. The chemical formalin is added to the live and feeding virus to destroy its polio-causing potency.
4. The now "killed" virus is safety tested first on laboratory animals.
5. After being checked and approved for human use, an inoculation is given and blood tests are taken to determine how effective the vaccine was.
Again the ease of explanation does not do justice to the many hours of careful preparation and calculations that must be made in the expensive, time-consuming and demanding job.
Dr. Salk, a devoted husband and the affectionate father of three small boys, drove himself unceasingly because, he says: "There was a job to do."
Asked how many hours a week he worked, he replied: "As many as are necessary."
Much as he enjoyed being with his family and relaxing at home to good music or on the tennis court, he cut out all activities.
"My work is my hobby," he once told a newsman.
It seems likely that history will single out two men in particular from the scores who contributed to the prospective conquest of polio - Dr. Enders and Dr. Salk.
But neither Dr. Enders nor Dr. Salk is resting on his laurels.
At this moment, they are working on new and improved techniques to combat disease.
