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If you like Jonas Salk's story, you might also like:
Tenley Albright,
Elizabeth Blackburn,
Francis Collins,
Gertrude Elion,
Paul Farmer,
Judah Folkman,
Susan Hockfield,
Louis Ignarro,
Eric Lander,
Robert Langer,
Robert Lefkowitz,
Barry Marshall,
Linus Pauling,
George Rathmann,
Oliver Sacks,
Thomas Starzl,
John Sulston,
Bert Vogelstein,
Dennis Washington,
James Watson,
Elie Wiesel and
Shinya Yamanaka

Jonas Salk's recommended reading: The Island Within

Related Links:
The Jonas Salk Trust
Global Polio Eradication

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Jonas Salk
Jonas Salk
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Jonas Salk Interview (page: 4 / 8)

Developer of Polio Vaccine

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  Jonas Salk

How prevalent was polio when you began your research? It's hard for people growing up now to get a feeling for what the world was like then? Who was it striking? How was it spreading?

Jonas Salk Interview Photo
Jonas Salk: Poliomyelitis struck first at infants. That was why it was initially called infantile paralysis. But as hygienic conditions improved, the virus spread in the population in a different way than it did when hygienic conditions were poor. When hygienic conditions were poor, many infants died of diarrheal diseases. In the course of the infection that was spread that way, perhaps by exposure to sewage and unclean environments, they would very likely acquire the poliomyelitis virus infection, which, if it occurred in the first six months of life, would protect them against paralysis because of maternal antibody. After maternal antibody was lost, and the infection was acquired after six months of life, then paralysis would ensue. So at first it was an infection that would occur within the first six months to a year of life, or two or three years of life. But as time went on and hygienic conditions improved, they were spared the infantile infection, but were exposed later when paralysis could occur.

By the time the early 1950s appeared, about 25 percent of paralytic cases occurred in those 21 years of age and older. In fact, Franklin Roosevelt, who was a president of the United States, was paralyzed at the age of 39. And so at that time the age distribution had changed. It was a disease that was spread less by water supply or by exposure to fecal contamination. It was spread now more by pharyngeal spread, in the family context or amongst playmates - the secretions of the nose and throat. Because the virus would enter the blood stream, it would multiply in the intestines, enter the blood stream, and then it would enter into the nervous system, the spinal cord -- paralyze -- but it would also appear in the throat. And then, it could spread that way in schools, and amongst playmates. Well that's how it was spread. As far as the incidence in the early 1950s -- in the five years before the vaccine was available in '55 -- about 25,000 cases occurred annually. The highest incidence was over 50,000 cases in 1953, I think it was. And this gives you some measure of the concern because it would crop up anywhere, at any time, without any forewarning.

What attracted you to the notion of using a killed vaccine? That goes back to your influenza work, doesn't it?

Jonas Salk: Yes, the reason for pursuing the idea of a killed virus vaccine is very simple. Before the work on influenza, the effective vaccines were those made with what we call attenuated, or so-called weakened viruses. They have the capacity to infect, but they are less likely to cause disease. Now sometimes smallpox or vaccinia virus -- which is the same virus that is used to make immunization against smallpox -- would cause serious reactions, and sometimes fatal reactions. There was a rabies vaccine that was made from weakened viruses. There was also a yellow fever vaccine that had been developed that was a weakened virus.

Jonas Salk Interview Photo
Jonas Salk Interview Photo

The principle that I tried to establish was really that it was not necessary to run the risk of infection, which would have been the case if one were to try to develop an attenuated or weakened polio virus vaccine. And so it seemed to me the safer and more certain way to proceed. That if we could inactivate the virus that we could move on to a vaccine very quickly. Whereas, if you were dealing with weakened virus, you would have to demonstrate its safety eventually. So, that was the reason and there was a principle that was involved. You might say a scientific principle, a fundamental principle: choosing and preferring that which the safety which you could control, and the quantities which you could use. So that this is, in a way, a more scientific approach. Trying to work like nature, instead of imitating nature.

Therefore, I wanted simply to select a variant that was weakened, you might say.

At that time I was behaving like a medical scientist. Exploring the limits within which one could effectively immunize with a non-replicating, non-multiplying virus. So, it was not a matter of why I chose that. I was investigating to see whether it could be done -- and it could be done. And, then we determined the parameters within which, in terms of dose and quantity and duration and persistence, and what kind of immunity, if an immune response was required. And that way, I began to develop an understanding of the principles of vaccinology as applied to polio miletus as well as influenza. So, that was the attitude that prevailed at that time. It was not simply empirical. It was a theoretical experimental approach.

You got quite a bit of flack for that because no one had done it before, and you were going out on a limb.

Jonas Salk: I wasn't going out on a limb. The flack to which you refer is what taught me, very early on, not only about the human side of nature, but about the human side of science.

There are three stages of truth. First, is that it can't be true, and that's what they said. You couldn't immunize against polio with a killed-virus vaccine. Second phase: they say, "Well, if it's true, it's not very important." And, the third stage is, "Well, we've known it all along." What you are describing is the process that you have to go through when you come up with an idea that has not yet been tried or tested.

[ Key to Success ] Perseverance

While it is true that this involves personalities, it also involves different ways of seeing. It was not a matter of a popularity contest, it was not a matter of anything other than that my curiosity drove me to find out whether it could work or not.

How did the criticism affect you personally? Were you hurt by it, or did you just plow on?

Jonas Salk: I just plowed on. Hurt? That's one thing. Being deterred is another thing. And so, while we prefer to have an open path, one thing you learn in life is that there is no such thing as a free lunch. There's no way that everyone is going to agree and particularly if you go against the main stream.

Everyone at that time had their minds set on how they thought the problem ought to be dealt with, whether it was influenza or poliomyelitis or now even the work on AIDS. That's a characteristic of what I like to call the "evolutionary process."

It's unnerving to find that scientists who are bent on helping mankind get into these very bitter rivalries. Is that just a part of the field?

Jonas Salk Interview Photo
Jonas Salk: The contradiction is in your assertion. You say these scientists have a bent to help mankind. That's not what their objective is. If that was their objective, they might approach it somewhat differently. That is not necessarily the case. The motivation that drives us to do what we do is different in each instance. You begin to understand, from the effect it has produced, what is the person's real motivation. There are two aspects to our pursuits. You have to deal with nature, as I do when I go into the laboratory and do an experiment, and you have to deal with the human side of nature, which concerns how colleagues or others will react. This is what piqued my curiosity early in life. It continues to pique my curiosity. That's what I think of as the human dimension.

It sounds like you have to develop a fairly thick skin in this field.

Jonas Salk: You have to develop a thick skin in life. It's not in this field only. You might think of the ideal of the scientists, the ivory tower, the idealist. That's true of some. And, I wouldn't guess as to what proportion. But there are some who are of that character, and there are some who are not. What comes to mind now, as I often think of this, it's like a sea gull syndrome. I call them sea gull syndrome. When I walk on the beach, I see the sea gulls, going out and getting a fish or a piece of bread on the beach. And the others go after him, that one, rather than go get their own. And so, I see sometimes that if someone does something and gets credit for it, then there is this tendency to have this competitive response.

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This page last revised on Jul 24, 2015 16:20 EDT
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