Dr. Walter Dowdle

Walter Dowdle

TORGHELE: It is May 23, 2016, and I'm at the Centers for Disease Control and Prevention with Dr. Walt Dowdle. My name is Karen Torghele, and I'll be talking with Dr. Dowdle for the Global Health Chronicles Polio Oral History project. The David J. Sencer CDC [Centers for Disease Control and Prevention] Museum is partnering with the Emory Vaccine Center to gather these oral histories to document the history of the Centers for Disease Control and Prevention.

By way of introduction for Dr. Dowdle, I will just briefly say a few things about him. Dr. Walter Dowdle was most recently consultant to the Task Force for Global Health and to the World Health Organization on the Global Poliomyelitis Eradication Initiative. He directed the Task Force's Global Polio Eradication program and initiative funded by the Bill & Melinda Gates Foundation. Prior to joining the Task Force, Dr. Dowdle was deputy director, Centers for Disease Control and Prevention, in Atlanta from 1987 to 1994, and acting director 1989 00:01:00to 1990 and in 1993. So, Dr. Dowdle, welcome. Thank you for agreeing to be here. By way of getting to know you for everyone, would you just tell us a little bit about your background and how you initially came to be at the Centers for Disease Control, and when?

DOWDLE: Thank you. It's difficult to know exactly where to start, but I think what I might do is relate a little bit of how polio comes into ending up at CDC. I guess my first real introduction to polio, if you will, was when I was at the University of Maryland working on a Ph.D., and there I was doing work with anthrax phage, which, of course--phage is a virus which attacks bacteria, and 00:02:00these phages attack the anthrax bacteria. And at that time, I had a professor of virology who really made a lot of impact on me and my thinking and career. And this was [Dr.] Maurice Hilleman. Maurice Hilleman, as many may know, is the developer of the vaccine, the so-called MMR vaccine--the measles, mumps and rubella vaccine--hepatitis vaccines, and, of course, he was behind the influenza vaccines for many years.

So there we got to work not only with polio, but also my first real introduction into tissue culture work. Tissue culture work, you have to keep in mind--that is, the tissue culture used for production of poliovirus vaccine--was only 00:03:00actually, you might say, discovered or rediscovered about four or five years from the time we started working on it. So, it was all very new. Everything was still new. It was all very exciting. All of this was still developing at the same time. This was about 1957-'58. And the Salk vaccine had only been introduced a few years earlier in 1955, in '56. So it was a very exciting time.

So I got into that area, and I guess it was really fortuitous. Actually, I had not applied to CDC. But CDC had actually asked the University of Maryland for them to recommend recent graduates of this, because of other connections. So I ended up here. But at the same time, I had really known the Montgomery [Alabama] 00:04:00laboratory back in the earlier '50s, because I'd gone to the University of Alabama and we had made a number of trips over to--there was a small virology unit in Montgomery as part of CDC. So we went over there to learn the fluorescent antibody technique, and so I knew and had had contact with a number of people over there before ever moving here. And it ended up that I came to CDC in 1960, which is the same time the laboratory moved from Montgomery over to building 7. So that all just sort of happened.

TORGHELE: Who were some of the people who were working in Montgomery?

DOWDLE: Well, the people--Schaeffer, of course, [Dr.] Morris Schaeffer, was really an extraordinary person. He had been pretty much dedicated to polio for a 00:05:00while. He was severely crippled from polio, which most people don't realize. But he was severely crippled. He had this interest in developing a live vaccine, like the Sabin vaccine as we know today, and had actually started one quite earlier. Then he had attracted to the lab a person by the name of [Dr.] C.P. Li, who was from Taiwan originally but was also interested in developing a live vaccine, so between the two of them they started trying to attenuate all three of the polioviruses to use them for the vaccine. And they were actually working on all three, but they did an extraordinary job on the type 1. That type 1 virus 00:06:00was the type 1 that Sabin used. He made a few more passages, but basically it's the same virus. And so that's the virus in the vaccine today. It all came from CDC.

TORGHELE: So Dr. Schaeffer and Dr. Li shared their strains of the virus with Dr. Sabin.

DOWDLE: Right.

TORGHELE: And that's the one that--

DOWDLE: That's the one was used.

TORGHELE: The strains are the same one that ended up in the vaccine.

DOWDLE: Right, yeah. And, in fact, it's known today as the Li and Schaeffer strain. So, that's one part of the CDC polio effort that I think most people don't really appreciate. But the Montgomery lab was involved in polio much earlier than that and in other ways. It also did a lot of the diagnostic work, and it did quite a bit of the virus surveillance work and virus typing and this type of thing. So when the lab moved from Montgomery over here, all of it moved 00:07:00over here at the same time in 1960.

Then there were other people. [Dr. Roslyn Q.] Robby Robinson, who also came to CDC at that time, was heading up the influenza laboratory. Then there was [Dr.] Roy Chamberlain, who you may have encountered. Roy and his group actually did a lot of work in arboviruses, showing how widespread they were, where they occurred, and introduced a number of the techniques that are used in arbovirus work. So, a lot was going on. There was [Dr. Robert E.] Kissling with the rabies work, who actually perfected the test for rabies and, of course, fluorescent antibody for rabies. A lot of good work went on, and I'd like to say the same 00:08:00thing happened here. So it was a very interesting time, and there were a lot of sort of interconnections. You know, don't forget, virology was a fairly small world then. You knew almost everybody in the field in one way or another. It was pretty small.

TORGHELE: How did you get interested in viruses as a specific--?

DOWDLE: Well, basically, as I said, I was originally working with anthrax bacteria, then the viruses of the anthrax bacteria, and then with Maurice Hilleman as my professor. I got interested in human viruses. That's basically how it went. Then when I came down to CDC, I worked on respiratory viruses and herpes viruses, influenza--that was the initial work that I did.

TORGHELE: And it was new.

DOWDLE: Yeah, it was all pretty exciting. One thing that I think tends to get 00:09:00lost--in about 1968 we had become convinced--or at least I had become convinced, here at CDC--of there being two types of herpes viruses. Then it turns out that my neighbor across the street here was [Dr. Andre J.] Andy Nahmias. Andy Nahmias--who's quite well known as professor at Emory University, now retired, of course--and it turns out that Andy and I were talking across the street, and he was talking about his interest in herpes viruses. So we joined forces and published the paper demonstrating that there were two types of herpes viruses. And at that time, all the type 1 occurred above the waist and all the type 2 00:10:00viruses occurred below the waist. So that was the first proof that there were two different types with two different tissue sources.

But I'm getting away from polio. But the polio interest really even continued then because when I came to CDC, the lab was finally open here in 1960. Then right around the corner was the polio lab, and at that time they were doing some very famous--doing the famous Atlanta study of the first trials of the Sabin vaccine before it was licensed. They discovered, as they were going to use type 1 and 2, that type 3 was actually occurring at that time. So that stimulated a 00:11:00lot of the interest in the Sabin vaccine, and I think was a major step forward for the vaccine. So that's one other area that perhaps people don't fully appreciate. And the person who was heading up the lab at that time was [Dr.] Henry Gelfand. Henry Gelfand had done just extraordinary work before he came to CDC, as the person who worked with [Dr. John P.] Fox to do all the family studies, and that had a lot of bearing on the selection between the Sabin vaccine and the Salk vaccine.

TORGHELE: You arrived after the Cutter incident. Did that have repercussions during the time you were here?

DOWDLE: Well, of course. I mean, it's true, I did arrive right after the Cutter incident, but it's sort of like events that happened in your family. It's still 00:12:00talked about, it's still very much of your daily life, because of people involved in it. Yes, that was a major event, but at the same time, it was resolved, and it was a matter of, simply, the virus not being inactivated adequately. Once those technical issues were actually resolved, then we went on and the Salk vaccine has never had an incident since then.

TORGHELE: How was the lab involved in identifying the problem with the vaccine?

DOWDLE: I should say not a great deal. Indeed, it was earlier, but largely trying to differentiate the types of viruses. But I was not directly connected 00:13:00with that at the time. But Montgomery lab was involved in that.

TORGHELE: You talked about surveillance in the lab. Can you say more about that, and how it worked with polio epidemics and vaccination programs?

DOWDLE: Well, it was the involvement of the lab in the early polio vaccine development. And the early application of the vaccine was in some ways just incremental steps in working with some of this, because they've been involved in polio isolation for quite some time, and diagnostic work with the states for quite some time. But it was a matter of volume, and it was a matter of accepting materials that were related to the whole issue of vaccine production, vaccine 00:14:00safety, and vaccine application. But still, the National Polio Foundation actually was supporting a lot of this work that was done at a university level, rather than at the CDC level.

We got involved, I think, in two ways. One is the Cutter incident, and I think this speaks a great deal to [Dr. Alexander D.] Alex Langmuir that Alex had sort of inserted himself into a lot of these issues that perhaps a government institute may not necessarily have been involved in at the time. Those were different times, and quite different. So he got involved in the Cutter incident, and his early, you might say, conclusions--that this was related to a particular 00:15:00vaccine and not the whole vaccine and not everyone's vaccine--I think pretty much put the spotlight on him. The work that was done by Langmuir's group, by the EIS [Epidemic Intelligence Service] officers at the time, [Dr.] Neal Nathanson who led this group, I think really put CDC in the spotlight. There was no question about it. Then once they were in the spotlight, then they sort of stayed in the spotlight from then on. Langmuir had already been involved in a number of the commissions and a number of the groups and at many meetings of which polio vaccines, applications, were the subject. But CDC at that time was not a major--wasn't involved in a major way in really developing the vaccines 00:16:00per se--except for Li and Schaeffer, and that was not field-related at the time.

TORGHELE: So the Epidemic Intelligence Service started out in 1951, as they were interested in bioterrorism and preventing that from happening in the United States, as I understand it. Did Dr. Langmuir use the polio-tainted vaccine as a way to get the EIS officers involved for that reason?

DOWDLE: Well, yes, that was the original idea. But I think the involvement in the Cutter incident and in the vaccines took on a life of its own. I mean, there's no question about it. Every now and then somebody would sort of bring it back to what the original intent was, but it was an event of its own in that respect.

TORGHELE: The National Institutes of Health [NIH] maybe would've been expected 00:17:00to get more involved, but it sounds like CDC did the majority of the work in the Cutter incident. Is that right?

DOWDLE: Well, again, this is, I think, the genius of Alex Langmuir. I think we can't really underappreciate what Alex had done for CDC, and made CDC in many ways. That one person probably made CDC more than anyone else has. Again, there were very strong personalities in those days, and there were the Harvard professors, and you don't see that so much today. It's much more of a teamwork type of thing, it's a group effort. But in those days, the individuals really sort of led the way--sometimes wrong, but often right.

TORGHELE: You mentioned Neal Nathanson. Can you say a little bit more about his role?

DOWDLE: Neal was the one who actually wrote all of the articles regarding the Cutter incident, but it was also very much a team effort, and he led a lot of it. Neal is a very good epidemiologist, but also a good polio virologist, and he combined the two. He's a very thoughtful, very independent thinker. Neal, again, is one of the people I think as an unsung hero of not only Cutter, but throughout his whole career.

TORGHELE: Getting back to the labs themselves, can you describe a little bit what the Montgomery labs were like when you would visit there?

DOWDLE: The Montgomery labs were pretty much like the old labs out at Chamblee. They weren't that different. They were in Quonset huts. This was at the old Maxwell Air Force Base and these were all leftover World War II buildings, and so they were in pretty bad shape both in terms of appearance and in terms of construction, but also problems related to holes in the floor and leaks. It was awful, really awful, but the job got done.

TORGHELE: When you all moved to the new labs in 1960, what were they like?

DOWDLE: The 1960 labs obviously were much better. I mean, you had brick instead 00:20:00of the Quonset hut type of building. You also had actually cooling and heating capacity, whereas they only had window units in Montgomery. Obviously, it was like going to heaven. It was so different. But yeah, when we look back at it, the buildings that actually we moved into in 1960 were pretty primitive, and they were basically just a structure with rooms. They did have hoods in them, but these were more or less sort of improved chemistry hoods, and not much more than that. And, of course, in those days we had--restrooms were both colored and white, and designated as such, and they were--we have to keep in mind that this 00:21:00building, though, was designed in the 1950s. So by the time it got fixed and completed, CDC no longer--well, it wasn't their idea in the first place, but CDC definitely--it was not in CDC's interest to do this. So all the bathrooms got converted. The 'colored' signs were taken down. That meant extra bathrooms, and so the ladies rebelled, and they ended up with more bathrooms in the end, so everybody won.

TORGHELE: I guess that must have been true for drinking fountains.

DOWDLE: Yeah, but I don't recall that that was labeled.

TORGHELE: Can you think back on some of the diagnostic tools you used, and some of the lab equipment that you used at the time, that people might not know about now?

DOWDLE: If we talk about polio-specific, there wasn't a lot of new equipment or 00:22:00fancy equipment that was being used. There were two things I recall at the time that eventually became quite popular. One was the use of the rolling drum, in which--you put your tissue culture tubes in this drum, and by rolling the drum, the tissue culture media would actually cover the tissue culture to keep it moist. So that was fairly new. That actually came out of the vaccine production. So this is a very small thing. The other item that was quite new at the time was the use of little small plates that were 96 holes, plastic plates, and that really came out of the plastic industry. That took a while to work out--some of 00:23:00the plates were very bad, some were toxic, but eventually it became the mainstay. So that was sort of new at the time. But basically they were fairly standard techniques that were being used back in the 1960s--not that exotic at all. Later, of course, it's a totally different world, with all the current work that's being done.

TORGHELE: What were the major changes that made the virology study more up--

DOWDLE: Well, let me go forward a little bit. When I became the director of the Virology Division, later on, is when I became really more immersed in polio. What sort of started that is that there was a case of paralytic polio in Texas, 00:24:00and this was a young girl whose last name was Reyes. This young girl had just had a dose polio vaccine, and she came down with paralytic polio in an area that wild poliovirus was occurring. So the lawyers for the family blamed the company for a vaccine-associated case, and so therefore they sued the company.

Now, that had other implications, particularly related to the safety of the vaccine and who will pay for it, and so on and so forth--who will pay for 00:25:00compensation. But for the laboratory, it was a different thing. For the laboratory, the question was, Why could you not tell the difference between a Sabin live vaccine strain and a wild strain? At that time, [Dr. James H.] Jim Nakano, who was running the laboratory, was using the standard sort of biologic test. And these tests were not sufficiently reproducible so that you could always tell the difference between them, because these were biologic characteristics, and they weren't always stable. So his testimony showed at the trial that this was a wild virus, but the jury didn't accept it because they had been instructed this was not something that was absolutely certain; there was some degree of uncertainty.

So at that time, I figured that despite all these other problems with the case, it was just embarrassing to us that we could not tell the difference--literally couldn't tell the difference between a wild and a vaccine strain. So at that time I said, We can't continue like this. We've got to come up with some way to tell the difference.

So at that time, I then put in for a position for someone who is new to the whole field, or would bring to us the competence in the field of molecular biology, which was just at its beginning, just at its beginning. So [Dr. John F.] Jack Obijeski came in to take that position, working with [Dr.Frederick A.] Fred Murphy, and so Jack then hired [Dr.] Olen Kew, who you, I'm sure, will be 00:27:00hearing about more with this group. And Olen Kew came in with the competence of working with polioviruses and the molecular biology of poliovirus. And so Olen very quickly--Olen and Jack and others--came up with this technique of oligonucleotide testing. This was also--when you look back on it--was extremely difficult, very complicated, but nevertheless you could end up showing the difference between the strains.

I think it was about 1979, about that period, we had this outbreak among the Amish. And Olen used that technique at the time, and for the first time you were able to really show that there were differences between strains, and this technique--and you could differentiate not only wild versus vaccine strains, but 00:28:00also between viral strains themselves. That was the beginning. That was an enormous step in the whole field of polio, just an enormous step. And I should point out that when he developed this technique, he went back and ran the virus that had been isolated from the Reyes girl. And it turned out to be wild, which was exactly as we had expected--but it was now confirmed to be wild.

TORGHELE: You couldn't prove it at that time, but later you were able to.

DOWDLE: This was in '79, whereas the Reyes case was about '73, I think. It was somewhat earlier, although he looked at the strain earlier.

TORGHELE: Were you called upon to testify at any of these other lawsuits that came up?

DOWDLE: No. Not in any. The other lawsuits--this was the only one where there 00:29:00was really a question about whether it was wild or vaccine-related. This is the main one. There probably were others, but that's the main one that sort of served as the history for the legal issues related to these sorts of cases.

TORGHELE: So, moving ahead, after the Sabin vaccine was used and Salk was discontinued--so the killed virus is not being used anymore, and attenuated virus vaccine was being used--there started to be some cases of polio that were associated with polio with the vaccine. Can you talk a little bit about that, and what the process was in discovering the association?

DOWDLE: The Sabin polio vaccines, live attenuated vaccines, actually were two types, I think, licensed in '61, and the other type 3 was in '62. And then its use became very widespread. But within the next year or so it became very clear that there were people who had immune deficiencies, and people who were older but somehow had escaped infection with polioviruses in their childhood years, [who] had actually become paralyzed from the vaccine itself. So this became very clear through CDC surveillance. CDC surveillance had been set up in 1961 and, again, because of Langmuir, and related to the Cutter incident. You see how it 00:31:00all is very much related. It all sort of falls into place. So through this surveillance system, it became very clear that these were cases related to the vaccine, called vaccine-associated paralytic poliomyelitis. And so the person who was pushing this and saying, Look, these have got to be vaccine-related, was Alex Langmuir once again, based on the surveillance. Of course, [Dr. Albert] Sabin was constantly denying anything, you know, always denying. He never accepted the fact that the vaccine would cause paralysis, but everybody else did. But Sabin would never accept it, or never admit to this. But that's one more step with putting CDC in the limelight.

One thing also was occurring about that time that I ought to mention is that the 00:32:00MMWR [Morbidity and Mortality Weekly Report] came to CDC right at that same time. In January of '62 was the first publication of the MMWR. And so using that MMWR, which was totally different from the way it was used earlier, CDC once again had really--if you will--a voice so that it was made public within the scientific sphere.

TORGHELE: And MMWR stands for Morbidity and Mortality Weekly Report.

DOWDLE: Correct.

TORGHELE: Every week a report would come out.

DOWDLE: Correct.

TORGHELE: Talk a little bit about that, if you would. Do you remember about when that started?

DOWDLE: Oh, yeah, exactly when it started. I remember it even being talked about, about, Oh my gosh, we've got one more bureaucratic thing to deal with. And at that time it was operated out of Washington, and at that time it was one 00:33:00of the most boring incomplete thing[s] you can image. It was just simply statistics. And we used to always say, It's how things were instead of how things are or how things should be. It was so out of date, so it was just nothing but--you know, once in a while it would talk about--they'd report on an outbreak, but it was only a couple of sentences. It became probably most useful during influenza epidemics, but still said very little and meant very little and had very little influence on anything.

But what Alex did--Alex saw once again that this was a big step for CDC, to have this type of thing available. And so he changed the whole thing around and made it a reporting mechanism which would be of interest to the public health, to the 00:34:00general public, and above all to the news media. All this was happening at the same time, and each one was just a step, one more step, in building the type of respect and the type of vision that he saw CDC in the future.

TORGHELE: And I guess the news agencies very quickly picked up on the fact that this is an important thing to pay attention to.

DOWDLE: Correct.

TORGHELE: Then reported on it after they got those MMWRs every week.

DOWDLE: That's right.

TORGHELE: So, were there other organizations that were involved in various stages of polio work that you can think of, that collaborated with CDC?

DOWDLE: Well, of course, CDC depended on the state and local, but particularly the state health departments. And that partnership is what has been so important. It was also important [in] polio and the polio surveillance early on, and it was also important in expanding vaccine use in the population. It was extremely important. So I would say those would be the chief groups that really cooperated with CDC and really helped CDC. Others--I think there would be other universities, but it happened to be who was working at the universities, and so I'm not certain what other groups. I may be not thinking specifically. We have 00:36:00worked in a number of occasions with vaccine manufacturers, vaccine developers, on studies over time, but these were not things we normally did all the time or had as a partner in all these areas.

TORGHELE: So it was very much a collaborative effort, and it sounds like what happened because of the leadership of CDC was that CDC wasn't forced upon the state and local health departments. They offered their help, and then if the local health departments wanted it, they--

DOWDLE: Well, that's true. It was very much collaborative, and it was very much each seeing the value of the other. So it was a partnership that sometimes was a little rocky, but it, again, depends on personalities that were involved. But I think there's another step we have to think about, too--is that generally if 00:37:00there's a question about reporting a particular agent on a routine basis, that decision was made collaboratively with the epidemiologists from the states and CDC. It was a joint decision that was made. It's not something that CDC said to the states, You have to report this. It was a joint decision which was made before the actual reporting. So that was a very, very effective way of getting buy-in from the states, because they were all a part of it. Then sometimes states didn't agree, or they may have agreed later, but it was indeed a collaborative decision.

TORGHELE: That must have enhanced communication and collaboration a lot.

DOWDLE: Yes.

TORGHELE: I guess now we should talk about [how] CDC became involved in global 00:38:00eradication efforts.

DOWDLE: Well, again, so much of--once the vaccines had been developed--and these were by very strong personalities and strong individuals who were involved very early on--and then once it became more and more of a national effort than a global effort, then partnerships expand. The number of people involved expand[s]. And so it's difficult, as time goes on, to say who was the real person who began this or began that. But the eradication program--just once, again, these little steps that sort of all came around. And it followed the smallpox eradication program and that successful effort, which--by 1980 the 00:39:00world was declared smallpox-free.

Now, in 1977 the World Health Organization had all these big events surrounding what was called the Alma-Ata Conference. And the Alma-Ata Conference is a conference that was titled "Health for All," and the "Health for All" meant that they would no longer have vertical programs. The vertical program means that you would actually make a determined effort and plan to get rid of or reduce the burden of a particular disease. And the case [of] smallpox was considered to be a vertical program. Other vertical programs would be immunization programs, for example. So they were saying there would be no more vertical programs, and WHO 00:40:00[World Health Organization] was dead set against having any more vertical programs. And yet at the same time, as soon as smallpox was eradicated, then there was an effort to start a program eradicating polio. WHO was dead set against it, dead set. So this is, again, in about 1980 when all this came about, to the point that when smallpox was recognized as finally being eradicated, that WHO had no celebration. The only celebration of smallpox eradication was here at CDC. That was it. WHO did nothing. So PAHO [Pan American Health Organization] started an eradication program itself back about '83.

TORGHELE: The Pan American Health Organization.

DOWDLE: Pan American Health Organization. And this was a program that really 00:41:00came about because of the success that Brazil had had using the Sabin technique of mass immunization. No one else except Cuba was using mass immunizations at the time. And Cuba has never had a polio case since 1960, since the vaccine was first used. I think they had two cases the first year. After that, they never had it anymore.

But people said mass immunization couldn't be used elsewhere--because Cuba is a small island, it was a Communist country, people always did what they were told to do, and so on and so forth, and it wouldn't work anyplace else--and so therefore that whole concept had been discarded. Brazil finally ended up perfecting it and using it, because everything else had failed. Everything else had failed. They continued to have outbreaks. So they sort of perfected it--not totally, but at least to the point that it worked for them. And this was because 00:42:00Sabin was pushing Brazil really, really hard. And then when it looked like it was going to be very, very successful, then PAHO--Pan American Health Organization--picked up the concept and said, We're going to do this for the entire American region, so that the region would be polio-free.

So it just so happens that Carlyle Macedo was the director of the Pan American Health Organization at the time, and he was also from Brazil. So the Brazilians sort of took over this whole concept, and, through Albert Sabin, Rotary [International] got involved. So Rotary started providing the money to get it started. CDC also contributed money to get it started. And CDC, through the virology division and through [Dr.] Mark Pallansch and Olen Kew, had actually 00:43:00set up the plan for the virology surveillance, which meant not only surveillance for polio, but also for the viruses and characterization of the viruses. So that was set up about 1983.

So it was doing so well that--it was really doing quite well using these techniques--that in 1988 there was the Talloire Conference. And the Talloire Conference, which--Talloire is a little small town outside of Annecy in France--and it brought together the World Health Organization, UNICEF [United Nations International Children's Emergency Fund]--UNICEF was a big pusher of immunization--and the World Bank. And people were there like [Dr. William H.] 00:44:00Bill Foege, [Dr.] D.A. Henderson. You see the influence of CDC. [Dr. Ralph H.] Rafe Henderson, who headed up the expanded program on immunization at the time, and others were at this meeting. And what came out of this meeting was the decision or recommendation that polio should be considered for eradication, which was so surprising because [Dr Halfdan T.] Mahler, [who] was the head of WHO at the time, had been the one behind the Alma-Ata Conference, which says "Health for All," and no more vertical programs. So he got converted at that conference and began then right away immediately. The conference was in early 1988, and by May of '88 he had convinced the World Health Assembly to go forward 00:45:00on polio. It was amazing. It all happened that quickly.

Well, when it happened that quickly, people in WHO thought this was just one more proposal and one more slogan and nothing would really happen. So it didn't go very far. In 1988, when the World Health Assembly resolved that polio be eradicated, not a lot happened. Very little happened. CDC sent people over to WHO to help start the program. Still not a lot happened. It was just an uphill battle. A lot of people didn't believe in it. The opposition to it was very, very strong. In fact, what really got the program started was CDC started 00:46:00holding meetings itself on eradication, and started inviting WHO people over. And we really have to give a lot of credit to people like [Dr.] Steve Cochi and [Dr.] Walter Orenstein, people that you all know who--Bob Keegan is another person who was really pushing on this very hard. We owe these people a real debt of gratitude, because they pushed the program when WHO was totally ignoring it.

And it got to the point where it started moving through CDC pushing it, particularly in China, which was a major step to get the program started. And it got to the point that about '96, I guess, that WHO decided it had gotten out of 00:47:00hand. So they brought the polio eradication meetings back to Geneva. But it was still another three or four years before things really got started. But when it did, it did quite well. But it brought in other organizations as well, not only Rotary, and of course CDC got much more funding. Rotary helped CDC get funding through Congress, and then the Gates Foundation came in later. So it was a wonderful collaboration that finally got started. But we talk about it, you know, it's taken all this long to eradicate polio, we're very close to it now, but at the same time a lot of this is just convincing people, getting people to join, and it's slow. It can be quite slow over time. So we did the low-hanging fruit, but it's taken until now to get to the point where we feel eradication is close.

However, to say that, we also have to recognize that during this time we've learned a lot. I mean, from the epidemiology we've learned much better how to actually work with populations, understand what populations want, to bring the people in and make people a part of it. We've also learned from the virology just some extraordinary advances that made the whole thing possible, because now the molecular biology techniques have developed and have, for a few years now, developed to the point that you can not only tell whether a virus is vaccine or whether it's a wild virus, or, if the wild virus, where it's from, how long it's been circulating--all of these things. Every virus had sort of a fingerprint 00:49:00that's based on these molecular biology techniques. So that made an enormous difference on understanding the epidemiology and understanding better the virus, and understanding what you have to do in order to design the program to stop transmission. So the virology has really made the major difference in eradication and the strategy for eradication, and it also is going to make the major difference for determining that eradication has actually occurred. To be able to prove that, it's all going to be based on the virology. So it's been a very exciting program.

TORGHELE: Can you say a little bit about what the arguments against it were? Because it's hard to imagine.

DOWDLE: Well, it's like everything else, I think, in public health--is that 00:50:00there's never enough money to go around. So the question is, What's the top priority, and where should the money go? As the old saying is, It's not so much what the money is going for, but what are the missed opportunities, what is the money not going for? So different people have different opinions as to what is the major public health issues which deserve most of the money. And I think [there is] a lot to be said about that. But at the same time, the smallpox program pretty much, I think, trained the next generation of epidemiologists, the next generation of public health officials throughout the world. And the polio program has done pretty much the same thing. It has trained not only people in different areas in public health, but also your next measles managers 00:51:00and so on. It's been an amazing opportunity to move public health forward worldwide.

TORGHELE: It sounds like they took lessons learned from smallpox eradication and have applied it to polio.

DOWDLE: Oh, absolutely. Not directly in the sense that the strategy was the same. The strategy was totally different, but at least the general approach, the technology involved and the people involved and the concepts involved are clearly stepping stones to polio eradication.

TORGHELE: In what ways did the strategies have to be different?

DOWDLE: Well, with smallpox, it was mostly visible. If you had smallpox, you had 00:52:00smallpox. Anyone could tell a pox. You may not be able to differentiate that from chickenpox, but anyway you knew you had a pox. With polio, polio only causes paralysis in about 1 to 100, 1 to 1,000 infections, and so therefore you can have a lot of silent infections and you never know about it. And the only way you can know about it is to be able to detect the virus, whereas smallpox didn't have that problem. And the other thing is that smallpox vaccine was a different virus from the smallpox virus, and so therefore the vaccine only actually replicated a few times and then it was gone. It wasn't transmitted on any large scale from person to person. The vaccine in polio actually is an attenuated live virus, and under the right conditions can actually revert back 00:53:00to its wild stage. And so therefore it requires a totally different approach to vaccination.

TORGHELE: We touched a little bit on the role that [Dr. Jonas] Salk and [Dr. Albert] Sabin played in all this. What were their stands on polio eradication? Did they get involved directly?

DOWDLE: Well, they were very much, I think, in many ways, vocal in regards to the program, but they weren't major players in the eradication program at all. Sabin was quite happy that his vaccine was being used, but Sabin early on--in the early days, his mass immunization, particularly in Mexico, that was being 00:54:00done, the work that was done in the Soviet Union at the time, was such that eradication was sort of obvious that it could occur in certain areas. But Sabin never really referred to eradication per se, because what he was concerned about, I think, is what most people are concerned about--is that distribution of the vaccine, and acceptance of the vaccine, was a lot different in developed countries than in developing countries. And just understanding the complexity of immunization of the number of people that were required to eradicate the program in these developing countries is just mindblowing.

So Sabin never really came out--he always said it could be done, but I think he 00:55:00had a little sense that it may not be achievable. A lot of people thought it wouldn't be achievable. Salk, of course, didn't have a lot to say, but interestingly--he died really before the program had actually gotten started in any extent, and Sabin, too. We'd have to look up those dates, but it was only in the early PAHO efforts that Sabin was involved, and Salk had very little to say about that. So it essentially happened after both have passed on.

TORGHELE: A lot has been said about their personalities.

DOWDLE: Oh, and it's all true. They were two very strong personalities. But Sabin could be just ruthless, but at the same time extremely charming. There was 00:56:00a third person in there that people tend to forget about, and that was [Dr.] Hilary Koprowski. And Koprowski was actually the first to produce an attenuated vaccine, and Koprowski was the first to actually test the vaccine in human volunteers. But that vaccine was considered to be too strong to be used in a wide scale, and so Sabin's vaccines were chosen. But I'm sure there's a lot of politics went into that as well.

TORGHELE: I was going to ask about politics, and the effect it had on a lot of the decisions and a lot of the things that happened around polio and polio eradication.

DOWDLE: Well, the old saying is that public health is politics, and it is, 00:57:00there's no question. It's the political process that generates funds, it's the political process that generates support. So, yeah, it is. It's a decision society has to make. Society has to decide, Do we spend this money on this project or not? So it's convincing them. But what convinced, I think, most of the scientific community that you should go with the live attenuated vaccine as opposed to the killed Salk vaccine was the fact that the work that had been done by Gelfand, who was here later at CDC. But before he had worked on these family projects with John Fox at Tulane University and in Washington, and they did a series of family studies. And in family studies you could see, in both polio 00:58:00epidemics and in trials with live vaccines, that people who had been given the Salk vaccine were pretty well protected, and in fact the protection was very good. So you were protected against paralytic polio. So that said a lot about the Salk vaccine. But when a wild virus came through, these people were not protected against infection, but they were against paralytic polio. So all the people who were protected with the Salk vaccine were infected with either the live attenuated vaccine or wild virus. There was no protection against infection, and so with all that evidence it was very clear that if you're going to eradicate a disease, you've got to be able to provide protection through 00:59:00natural infection. So that's why the live virus was accepted and considered to be the preferred vaccine.

Not all countries switched. Many countries continued Salk vaccine and had no problems, but they were also all developed countries with high standards of living. So it was that. The other thing that made the Sabin vaccine so popular is that it cost one or two cents per dose and it did not require a professional in order to administer it. There was no injection. You just simply swallowed the vaccine and that was it. So the advantage, the field advantages, the practical advantages, it was just no contest. And yet, ironically, we're now back to where we're using the Salk vaccine and are phasing out the Sabin vaccines altogether. 01:00:00And the reason why the Sabin vaccines are being phased out is that type 2, for example, no longer exists in nature. Type 2 Sabin is no longer being used. It's been replaced by the Salk vaccine, and the reason why is because, once again, the whole problem of the attenuated virus being able to revert back to a virulent form, and so that has to go. I mean, when you have thousands and thousands of wild cases, a few vaccine-related cases are a small price to pay. But when you have no wild cases, then even a few cases of vaccine-related virus cases makes much more of a difference.

TORGHELE: In the process of people giving the vaccines in various places, 01:01:00especially war-torn areas, were there people who lost their lives when they were doing the immunization programs?

DOWDLE: I think here, more recently in the high-security areas--and I don't know what the number is now, but there have been a number of local vaccine administrators who have lost their lives in these areas, particularly in the Afghanistan-Pakistan areas, but also in Africa as well, particularly in northern Nigeria. And for CDC people, I'm not aware of anyone in particular from CDC who lost their lives on the polio program, although there have been others in other programs. But yeah, it has been a real problem in these difficult security areas.

TORGHELE: I'm interested in how they surmounted those obstacles in the war-torn areas. I know that Nigeria was one of the last places to be successful in eradicating polio. How did they work around that?

DOWDLE: The big problem in Nigeria was that somehow the word got around that the polio vaccine was being produced with pig serum and with pig trypsin. So the imams in northern Nigeria--which is a Muslim area, in northern Nigeria--had decided that, Well, that was it, that wasn't acceptable, could not be accepted. And so they essentially refused to participate. So the whole area of northern 01:03:00Nigeria essentially had no vaccines for several years, and that really set the program back. But the southern half of the country had continued to take the vaccine, and there was essentially no cases unless it was imported from the north. So that was the biggest problem. And so it took some while and Gates Foundation, World Health Organization, and a number of other agencies to work with these imams try to get organized, and to try to work with them to [assure] them that this was not a problem. And it took some persuasion, because once you've made edict, to say that this is this, this, and this, you know, then [it is] pretty hard to go back and say, I was wrong. So how does everybody save face? It just so happens, though, that one of the producers of the vaccine was 01:04:00actually in a Muslim country in Indonesia. And so that was a big help, to say, Okay, all these vaccines will be coming from Indonesia, and so therefore there's no possibility of pig serum or any contamination of swine.

So that was the biggest problem. As far as the security, it's amazing what people do. I mean, they are so committed. It's just amazing how--particularly in Pakistan and Afghanistan--how they risk their lives to actually administer vaccines, not just polio, but other vaccines as well.

TORGHELE: So Pakistan and Afghanistan are the two remaining countries that still have polio. [NOTE: since this interview, three polio cases have occurred in Nigeria in July-August 2016]

DOWDLE: Correct.

TORGHELE: So what is being done in those countries, and what's your expectation 01:05:00for those two to eradicate polio?

DOWDLE: Well, a lot has happened. For one thing, there is now a military escort to help the vaccinators in these areas of security concerns. That's one thing. The other thing that they've tried to do is just intensify the programs, which it has been--So we're down now to about ten cases, I think, since the first of the year, in the world. And it's just in those two countries. So I think we're very close, and if we can just cross our fingers and hope there are not more security issues that might slow things down--There's still areas we can't get into, but also some of these areas there's issues of actually population 01:06:00movement, and opportunities to get to some of these populations without necessarily going into these areas of security needs.

TORGHELE: It's really exciting!

DOWDLE: Oh, it continues to be.

TORGHELE: I guess we should wrap up, because I know you've got some time constraints here, but I wanted to give you a chance to bring up anything you would like to include related to polio and CDC, or specific people you'd like to mention.

DOWDLE: Yes. I think sort of as a postlogue, if you will, the next thing we have to do now is that--once polio has been eradicated--is to contain the polioviruses in the world in the laboratories. And it's a humongous problem. So 01:07:00think of all the polioviruses and all the laboratories of all these years, and the polioviruses and many specimens, many samples that have been taken that may contain poliovirus, but nobody knows about it. For example, if you have been working in areas that have had polioviruses being transmitted for many, many years, and during that period of time you've collected stool samples for rotaviruses or stool samples for noroviruses or this type of thing, so all those samples probably have--I mean, many of those samples have polioviruses in them. So the question is, how do you deal with that? So if you've got all these materials stored which could be contaminated with polioviruses, how do you deal with that?

And that's the big issue right now, is how do you keep those specimens, if 01:08:00they're essential, from an infection which is purely accidental, if you will, into a laboratory worker, into the community, and repeat transmission all over again? So it's a major, major job, and that's a lot of the effort that's being devoted to right now. Again, CDC plays an important part in this whole process.

TORGHELE: I imagine that there's a lot of meetings involving the CDC and other organizations that have the virus, to work out a way.

DOWDLE: Absolutely, and there's many, many laboratories out there that are so-called non-polio laboratories that have polio in their possession and don't know it.

TORGHELE: I'm glad there are people who anticipate that problem and work out 01:09:00solutions before--

DOWDLE: But, I mean, what we're trying to do, basically, is to prevent any inadvertent transmission. Because you can prevent transmission with the right containment facilities and the right procedures and this type of thing, but it's a matter of getting people to recognize that they could have the virus, and actually to reduce that potential exposure as much as possible. It can be done, but it's just a lot of work involved. But it's the type of work you feel like you do very happily, because it's a post-step, not part of the process of eradication.

TORGHELE: It's a nice problem to have.

DOWDLE: Right, nice problem.

TORGHELE: Are there any other people that you would like to mention who you had interactions with or you know about still at CDC in polio and polio eradication, 01:10:00that we didn't talk about?

DOWDLE: Within CDC? Well, interesting thing. I should point out that, once again, there are major heroes back during the early days just simply developing--even before development of the vaccine--but developing our understanding of polio and the virus and epidemiology and all of this, that goes way back to the '20s and '30s, and remarkable heroic things that these people did.

But the debates between Sabin and Salk over which vaccine--the person who turned out to be right in all of this was Joe Melnick. And Joe Melnick was, at that 01:11:00time, a professor at Yale University, where [Dr.] Dorothy Horstmann was. Dorothy Horstmann is another one of these wonderful human beings that just had remarkable insight to what these issues were and how they might be resolved. She played an incredible role in the whole thing. But Melnick used to say there is no--well, I'll back up. Sabin and Salk used to say that one thing that they agreed on was there was need for only one vaccine. And each, of course, thought it was their own. Melnick used to say there's one thing he agreed on, is that it should be both vaccines.

So he was right. I mean he turned out to be right. Had both vaccines been administered, we wouldn't have had a lot of the problems that we had in the process. And it took a while, once again, for the learning curve, and to 01:12:00recognize that the two vaccines together would've been the best solution all along, and it was just a mistake to go with one or the other, because neither one by themselves would've been totally sufficient to get the job done. And when Bill Foege tried to introduce that concept back in about '89, '90, something like that, virtually I felt he was treated very unfairly, because the whole attitude of the group and the group thinking was such that it was just totally out of the question. I think he did a very brave thing, but it just didn't get a lot of traction at the time. So had we gone [with] Melnick and Bill Foege's proposal, I think we would've been a lot better off.

TORGHELE: And Foege would've had a lot of credibility because of the smallpox eradication.

DOWDLE: Absolutely, a lot of credibility. Sure, a lot of credibility in polio. But he took more of a--he was strongly supportive, always has been, of the program, but he took a little back seat after that, after his proposal just seemed to have gotten no traction and a lot of opposition at the time. But he was right.

TORGHELE: D.A. Henderson is another name that comes up. He was, of course, a big name in the smallpox eradication. Did he have a stand on the polio eradication?

DOWDLE: D.A. Henderson was head of the smallpox program in WHO, [and] was a CDC employee. In fact, D.A. Henderson was the first editor of the MMWR and also had a lot to do with how it was shaped, and so we owe him a great deal for that. But 01:14:00D.A. essentially opposed the polio program. Always did. He just fought the program constantly, and to the point it wasn't helpful at all. And it's too bad, because D.A. could've been extremely helpful in the program. But he felt like, much like others, that the job was just too overwhelming, it would cost too much money, and other things could be done, and smallpox was easily eradicated, polio would not be, and so on. So, haven't heard a lot of D.A. in the past four years, five years.

TORGHELE: So it was a matter of allocation of funds for him and for others?

DOWDLE: Well, it was not just allocation of funds, but also the complexity of 01:15:00the job and whether or not you could actually eradicate the virus, given the complexity of not only epidemiology but also the ability of the virus to mutate, so on and so forth.

TORGHELE: Very complex.

DOWDLE: Very complex.

TORGHELE: There's one more involvement that I wanted to ask you about. I was just reading that after the moon landing--

DOWDLE: Oh, yeah.

TORGHELE: You were asked to do a special job related to the moon landing. Can you just tell us a little bit about that?

DOWDLE: Oh, yeah, that was quite interesting. Yeah, they decided that when the astronauts came back from the moon and would be landing, then the question was, would they be bringing anything back from the moon, or would any of the samples 01:16:00from the moon contain any agent--infectious agent--which may just multiply widespread here back on earth? And so we were asked to come up with programs and procedures to test--not only have the astronauts in quarantine, but also to test the specimens that came in. And that was one of the highlights of my life, to be able to take these ground-up moon rocks and put them in tissue culture. And as I had told them over and over again, You know what happens when you put rocks in tissue culture? But anyway, we went through all the procedures.

TORGHELE: And we were all safe because--

DOWDLE: Yeah, we were all safe. You know, it was a thing that people said, Well, you never know, you don't know. And so, when we had a meeting here with the 01:17:00people from Washington with NASA [National Aeronautics and Space Administration] to try to come up with procedures and so on, it wasn't taken very seriously. Finally the guy said, I know. He said, But the president says we'll do it. So we said, Okay. That was it. No more questions.

TORGHELE: It would be interesting to see the write-up of that.

DOWDLE: Yeah. No more questions.

TORGHELE: I want to thank you for being a part of this oral history. You've provided lots of details that we never would've had.

DOWDLE: Thank you.

TORGHELE: And I think you made it obvious why lab and surveillance and epi [epidemiology] people universally respect you and like to have you at meetings, because you're a good listener and you sum up everything beautifully at the end. So thank you very much, Dr. Dowdle.

DOWDLE: Thank you, Karen.

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