Focus 580; Plague Time: How Health Infections Cause Cencers, Heart Disease, and Other Deadly Ailments

In this our focus 580 We will talk about how we are changing the way that we think about diseases diseases like cancer heart disease others for example we have. It has been our habit now to think about these primarily as the result of genetics and also of lifestyle. However there are a number of researchers that are starting to look at a different sort of analysis of these kinds of diseases and have suggested that in fact many of them may be the result of. Infections that they are viral in their origin. I will be talking this morning with Paul Walt he is a biologist hes professor of biology at Amherst College. He has been featured in a number of publications including The Atlantic and Newsweek and discover he is the author of a new book that explores this territory. The title of his book is plague time how stealth infections cause cancers heart disease and other deadly ailments. It is published by the Free Press and is out now it came out

in the fall. So you should be able to find it in bookstore if you'd like to read it. And also we are here An open to your questions if you'd like to talk with them. All we ask callers is that people just try to be brief in their questions so we can keep things going. But Anyone's welcome to call here in Champaign Urbana the number 3 3 3 9 4 5 5. We do also have a toll free line and that was good. Anywhere that you can hear us and that is 800 to 2 2 9 4 5 5 3 3 3 w y l l toll free 800 1:58 w whilom. Professor you all tell. Hello thanks for talking with us today. I have to appreciate it. I guess to where to begin. Maybe we could talk about the term we could define the term virulence. Is it something that you deal with right at the beginning of the book. And in this way because when we think about infectious diseases I'm sure that most people think

of them as you suggest in the book and I think you're right about it very nicely. You're right. Typically acute infectious diseases turn quick profits for short term gain the pathogens that cause them are corporate raiders out to get rich quick rather than maintain the health of their targets. And that's kind of the way we think about infectious disease it's something that comes on suddenly within a relatively short period after the time that the you get the bug. Generally speaking if we're lucky our immune systems eventually kick in as with a cold for example and take care of it. But here now we're looking at a rather different sort of a model. How in fact does the CS would work. Right well getting back to your first question virulence really just refers to how harmful the info the disease is so virulent of an infectious disease would be you know measured by how likely it is to cause a person to be incapacitated or how likely it is to maybe cause the person to die. And so when we're talking about infectious agents the virulence

of an infectious agent would be the inherent harmfulness of that particular agent. But your more general question is I think addressing the heart of the matter and that is that it was easy for us to recognize these acute infectious diseases things like chicken pox and smallpox and in fact these diseases were recognized as caused by infection 100 years before the organisms were identified. Even before the germ first part of the germ theory revolution occurred in the latter part of the 100 century so far back as the 1840s 1830s people realized the chicken pox and smallpox were caused by infection they don't really understand that clearly what infection was but was something growing inside of people to be transmitted from one person to another and people recognized it because. You could see it in their daily lives. Your child gets chicken pox and then the Playmate of the child gets chicken pox 10 days later and the playmate of that playmate gets chicken pox 10 days later. So if you know you didn't have to be brilliant deductively to realize that something was growing inside of people and being transmitted. But

from their early eighteen hundreds all the way to the year 2001 there's been this steady process in which we've every decade recognized more and more diseases are caused by infection. And any decade people have sort of thought well now we understand infectious diseases. And so in the late 1970s or late late 19th century people were arguing about whether the sexually transmitted diseases were caused by infection whether diarrheal diseases were caused by infection. Now at the beginning of the 21st century we're arguing about diseases that if they are caused by infection they're caused in so much a more cryptic way that it's very hard to get the evidence to conclusively demonstrate it. In fact what we've learned in the last 20 years is that we can't use the old standards of evidence to agree on whether a disease is caused by infection because the old standards were based on different kinds of diseases the old standards like Koch's postulates for

example which argues that you have to take the organism purify it and infect a model or perhaps a human if you've got an ethical. One way of doing that. Let's see if the if the suspected pathogen was extremely mild. And then ice will generate the disease and then isolate the organism again from the diseased individuals. This was the one of the old standards and it just doesn't work for the diseases that we're now recognizing as being caused by infection those that we recognized in the last two decades as being caused by infection. So it's never really been satisfied Koch's postulates for example never been satisfied rigorously for the diseases like cervical cancer which everybody agrees is caused by infection. Or for liver cancer much of which is caused by infection or stomach cancers or peptic ulcers for that matter. So finally after we've we've recognized sort of grudgingly I think that we have to keep changing our guidelines for accepting infectious causation as we solve the easy

problems e.g. problems of infectious causation and we move towards the more complicated examples the more cryptic examples of infectious causation. When we realize that we have to do that we always have to be on the move. Then we've begun to make more progress in identifying that a lot of these chronic diseases are caused by infection know the difference between acute. Diseases and chronic diseases and with regard to infectious diseases is really one of time. The acute infectious diseases as you mentioned come on strong and typically the immune system knocks them out within a matter of a few weeks and then the battle is over. But for chronic diseases you have. Disease organisms coming in and for one reason or another they have abilities to persist inside of the body. And so you may not even see any obvious signs of infection early on the maybe almost no symptoms of infection early on. But over a period of years decades sometimes as much as a half century the negative effects may arise sometimes

arising very gradually or sometimes arising quite suddenly. And now that we've sort of moved into this phase of this. It's becoming clear that we have to be continually changing the way in which we decide to agree or not agree on whether a disease is caused by infection just to give you a quick example. One of the chronic diseases that has been accepted is caused by infection in the last two decades is leukemia called adult T-cell the Kamya and people who are developing the Kamya are typically infected when they're born for mother's milk and then they develop the leukemia anywhere from 40 to 80 years later. So how do you actually satisfy something like the Koch's Postulates. If you've got a disease with a 60 year lag time I mean where are you going to use and going to mouse That lives for 60 years. And in fact in this case you can't even duplicate the disease in

any animal model. So what we have had to do in the last 20 years is to look very carefully and really I think much much more thoughtfully at patterns epidemiological patterns. Where is the disease present is the disease so firmly linked to particular disease organisms that no other explanation makes any sense. And if no one can think of any other reason electical nation then Medicine says Okay. Disease now we accept as being caused by infection. So there have been about 15 or so diseases in the last 20 years. Chronic diseases that have been accepted as being caused by infection things like cancers I mentioned and we've got another 15 or so of the major diseases chronic diseases that are killing us now in America and other all throughout the world. They are strongly suspected as being caused by infection. In fact the evidence is so strong that if you were to just bring people into the discipline show them the evidence for all of the various explanations people would say

Wolf of course infection is probably going to be at the heart of the pathological process. Now it's important to realize that saying that infection is a primary cause or a major cause of these chronic diseases I'm talking about diseases like atherosclerosis and heart attacks and stroke and Alzheimer's disease the major mental illnesses like schizophrenia and autism and bipolar disorder cancers most most of the cancers probably at least 15 to 20 cancer percent of the cancers are now accepted as being caused by infectious agents and I think it will probably end up being more like 80 or 90 percent will turn out to have infections. Playing a primary role. So now as we look at these these chronic diseases that are really major sources of morbidity and mortality. In populations like the American population and if we find an infection is playing a major role we have to be very

clear that just because infection is playing a role doesn't mean that genetics and lifestyles are not playing a role. In fact for every infectious disease that we understand well there are a host genetic that a human genetic predispositions. And there are also lifestyles or environmental noninfectious environmental influences. And so this is a very important thing to consider because what's happened in the last 50 years is people have gotten so focused on genetic causation and environmental causation of disease lifestyle influences on disease that they when they found some associations they then made the very important mistake of assuming that the positive support for environmental influences on disease or genetic influences on disease. Excludes the possible role of infectious causation and that's been a terrible mistake you can see why that would be a terrible mistake just by looking at the

diseases that everybody recognizes are caused by infection. So for example for tuberculosis we know there are genetic predispositions for tuberculosis but we call it an infectious disease because we know that if you eliminate the organism you don't get the disease. So I think that's what we're going to find for these other diseases as well that when we eliminate the organisms we sense we don't get the disease. Let me at this point probably introduce Again our guest for this hour focus 580 We're speaking with Holly Wald. He's a professor of biology at Amherst College. If you're interested in reading some more on this subject look for his book plague time how stealth infections cause cancers heart disease and other deadly ailments came out in the fall published by the free press and getting a lot of attention in media and your questions here on the show are also welcome 3 3 3 9 4 5 5 toll free 800. 2 2 2 9 4 5 5 2. To the extent that people think at all about how infectious diseases operate I'm sure as we talk a bit about the beginning their idea is

well you have this bug. It gets into the person and it uses the person as a host to very quickly reproduce itself sometimes at the expense of the host just burning up the person and that very quickly does this very quickly and then it very quickly jumps from one person to the next person and repeats that over again and then jumps to the next person. If you though think about it from the I'm interested that in the book you you think about things from the germs perspective if you think about it from the germs perspective what is what's in it what sort of advantage might be posed or might come with operating in this stealth mode where you have the infection that's there. May be there for long periods of time with maybe no symptoms or symptoms so subtle that it could be that years or maybe even decades could go by before the person came to realize that something was was wrong something was going on. Well to a large extent this depends on how the disease organism gets transmitted.

So typically when you look at the respiratory tract infections they tend to be the garden variety acute infectious diseases. They're causing a flood of production of viruses or bacteria and then people are sneezing or coughing and then transmitting these bacteria or viruses to other individuals as a result of moving around in coming close contact with susceptible for some kinds of transmission. The premium must be on persistence inside of a host and the two kinds of transmission that probably fit this idea the best of our transmission by what we can think of as hardcore sex or soft core sex hardcore sex would be you know what we think of as normally sexually transmitted diseases. Genital contact. Soft core sex would be things like kissing. But in either case because people aren't going around having as much sex with other people or kissing other people as much as they are going around sneezing and coughing on other people.

There has to be a premium from the pathogens point of view there has to be a premium on long term survival inside of the host. OK so what does that mean it means that the pathogen has to have tricks up its sleeve for avoiding the immune system. If it doesn't have those tricks up the sleeve it just out of the game right away because it's got to last for sometimes months or even years in order to get transmitted. OK so now the question is if it's got tricks up its sleeve what will happen over the long run. If it is void the immune system then sensual what you've got is something like a wrench in machinery the wrench doesn't end up messing up the machinery in the short run and may mess it up in the long run. And so what you typically have are diseases that are associated with this messing up the machinery and it gets compounded because some of the ways in which these disease organisms avoid the immune system involve living inside of the cells and sort of taking over the cells and pushing them a little bit closer towards a disease state that can be

life threatening for us. So for example we talk a little bit about the human we talk about cervical cancer which is caused by the human papilloma virus and the human papillomavirus. Can avoid the mune system by getting into cells and integrating into those cells DNA and then causing the cells to divide and it can also as a result of the protein that it codes for. It can make the cell unable to destroy itself. And it can also activate the cells. It can also make it so that the cells cannot shut down their reproduction in response to detection. Something wrong in the cells like genetic damage. So what this means is that the papillomavirus can have sort of a free ride a relatively free ride. It can get itself its living in to divide. It can divide right along with it because it's inside the cells not really very much exposed. The immune system.

It can be replicating itself without risking very much in the way of destruction. So the problem for us is that by short circuiting those measures that the cell has for controlling its own replication the virus has pushed those cells towards cancer. Now if you have just one or two mutations in addition to those changes that the virus is introduced you may get full blown istead of cancer which can be life threatening. So the idea is that. There's a conflict of interest between these pathogens the pathogens and in this case the papillomavirus which is sexually transmitted has to live inside of a host for a long period of time. S to avoid the mune system it's devised or evolved very fairly clever ways of manipulating the cell so that it can replicate without getting destroyed by the immune system. And that's just pushed the system closer to cancer. And what happens is in small proportion the people who

are infected with the cancer causing Syrah types of human papillomavirus you actually get the cancer and if those women haven't had their absent here they don't get that beginning stage of cancer detected and they don't have appropriate interventions then they may run the risk of dying. We have a couple of callers here. Let's bring them into the conversation starting with the Belgium line number. For how long. Yeah I am. I think I've discussed this in the past with you Mr. Hanson a couple other guests mentioning that it may seem very dark but I'm virus is just another way of controlling the population or disease is just a population human beings on the earth. I mean we have no other natural enemies. You know everything has its own way of being eaten or eating. Isn't this just something we're never going to be able get rid of. It is a controlling factor firm for our population.

Well we've got much better ways of controlling our own population than by relying on viruses. One one one way that's probably the most effective of all is improving standards of living in that and then giving people the option of birth control that has so effectively controlled the population size in places like United States and Europe that population is actually declining in these areas. So I definitely I mean there are other ways one could imagine controlling populations eyes like genocide. But there are certain ways that are not acceptable to us and then there are some that are very much acceptable I think the the idea that we allow people to have options that allow them to choose not to have kids. No sir I think you're missing the point I'm trying to make the point I'm trying to make is the natural world itself is going to find a way to control things. I don't know that. No that's this is a very important point and it is the misunderstanding that people have about it about ecology in

general. In fact this is where my training was in ecology and evolution to begin with. So I'm pretty familiar with this. The important point is that that there will be in this this first part is consistent with what you're saying is that population sizes can't grow indefinitely something's going to limit them it's either going to be food it's going to be predators it's going to be parasites. OK but now having said that then I think we move from the way things are to that with the way things are the way we can control things in our society and basically we make decisions so that we will. Cause you know basically we have options some options are going to be much more painful for people. Some are not and more generally some options are going to be consistent with the values that we hold dearest and some aren't. And so in this case.

What I'm the point I'd like to make is that the decisions that we have are do offer many very favorable opportunities and some of those favor alaap opportunities involve knocking out pathogens that are particularly destructive there's no reason why we should feel that we have to live with certain kinds of Atherton's we've been very successful at knocking out some of the worst ones. And once we understand that diseases are caused by pathogens then we can continue to do so. But in just the last point I want to make is that sometimes people feel that if you knock out one pathogen another pathogen will come in it takes place and there's really no basis for believing that. The evidence so far indicates that if you knock out a pathogen it isn't going to be that another pathogen will come in take its place. The more appropriate way of looking at this is that if you have pathogens that you that are causing problems you can nudge the system so that you favor some

competing pathogens with others. They will typically be pathogens that we link together in the same species and so there are many very powerful ways of doing this for example ways of making vaccines so that you favor the mild strains over the harmful strains. But I think it's very important not to just jump to this conclusion that pathogens have been here for a long period of time and so it's inevitable and they're a natural part. And so therefore this is the final step of the logic that I would disagree with. Therefore because the natural that we have to somehow put up with them. Your last point got to the point I was referring to. Thank you very much I mean thanks. Well it seems that in as I as I hear the caller he seems in a sense to be posing or perhaps I'm putting words in his mouth posing the question why. Why is there disease. No I think he might have been I might my sense wasn't in his last comment I think it made me confident that this is was the right interpretation of

his sense. But my sense was that he was thinking about it as being natural and so is that is there really anything we can do about it. But did you want to. But then I guess I'm thinking of the question is there. If it if one approaches is from the point of view perhaps of the evolutionary biologist is does disease perform a function or then are we imputing to it some intentionality that it doesn't have in in fact all viruses are doing is just like every other life form they're just you know trying to make a living. That's the other part is the right answer. I mean if that's not the right answer then we've misunderstood almost all of what has now become the basis of evolutionary biology and ecology for the last 20 30 years. In fact we have to generate something astonishing and completely different from what we now have as a basis for these disciplines. Yeah basically it's that when you have these different organisms whether they're viruses or bacteria or humans

you've got it. Competitors within each of those species of organisms competing with each other to make use of resources in the environment and to grow better than their competitors would reproduce and survive better than their had interests competitors would and that's what creates the world as we see it. And now we have to look at that world there and we say there are certain things about that world we don't like we don't like dying of cancer for example we don't like dying of acute infectious diseases. And so how can we interfere with that nature in order to make it so that we don't have the negative things we don't like and we're left with the things that we do like. Let's go again to another caller this is Urbana line one. Yeah I was marked with one as you know. Is it that in principle always possible to develop a vaccine.

Not always but the track record for dealing with infectious diseases has really been remarkably good. This is a bit of an irony when you look at where the attention has been spent in the last 50 years. It's been so much attention directed towards let's say identifying genetic causes of disease and particularly focusing on an idea that maybe there are some bad genes around even if we found those bad genes. The question is what would we do about it. We don't have a very good track record of dealing with genetic diseases. In contrast when we look at the history of dealing with diseases once we know that are infectious once we know that they're caused by infection then there are all sorts of things we can do it doesn't mean that every time we'll be able to get something that's effective but more often than not we can generate a combination of hygienic improvements to reduce transmission vaccines to stimulate the immune system so people won't get infected and or anti-virals or especially antibiotics that can help people once they are infected.

And so I think this is incredibly encouraging that these chronic diseases now are turning out to be caused largely by infection. But in addition to this more rosy outlook that one can generate by. Looking at the possibility that these diseases are really caused by infection they're also theoretical arguments and then there's the data itself that indicates that this is the right answer. That for example genetic bad genes just aren't going to be the major part of the explanation for the growth. My question my question is if there is in fact. Is it possible that principle to develop a vaccine against it. Well I don't know how to try to answer that by saying that our track record has been very good. Now when you say is it always possible in principle to generate a vaccine. Yeah in principle yes one could always develop a substitute

proof out of this. Possible but even ordered a theory even if that's a good point because if you were to if you had a candidate pathogen and you weren't really sure that that pathogen was causing the disease then you could generate a vaccine and if you get if you vaccinated everybody with that vaccine and you eliminated the chronic disease then you would have satisfied everybody satisfied. That's romantics. The only problem with that is that you're not going to get approval to use the vaccine unless the people are already agreed that the pathogen that you're trying to control is the cause of the disease. If you're trying to vaccinate against And so you have only a limited number of possible. Diseases for which that kind of approach would provide the critical proof. So for example if you were to make a vaccine against some acute infectious disease that was that was known to be caused by an agent that was also

suspected of causing a chronic disease and you eliminated the chronic disease by using the vaccine to control the cute infectious disease then that would provide that kind of proof. But many of these chronic diseases probably don't have much if any of an acute phase. That's what makes them so cryptic and that's why we're arguing about them right now is is that unlike the chronic diseases that we've accepted many of the chronic diseases we've accepted as being caused by infection which had very clear cut acute phases. You know tuberculosis or for syphilis for example a successful vaccine could be developed. This has an acute. Well I'm saying that you could if you have a suspect pathogen you could make a vaccine against that suspect pathogen. But I doubt that you're going to get approval for using the vaccine to control a chronic disease that doesn't have an acute phase because there are always risks associated with the vaccine the first

vaccine developed without having to be specific. Do you know when I survive it. I'm sorry say it again. The first fact cowpokes. Oh yes one that's involved with the death and why that's sort of a different situation. The first smallpox vaccine was generated by Jenner over 200 years ago because he noticed that people who had these cowpox lesions didn't get smallpox and so he figured there must be something in those called pox lesions protecting the country play that game. Yes but see that's not it's not quite the same as a couple things are different now. One thing is there's a lot more regulation now than there was back then. But also remember then at that point Jenner was dealing with an acute infectious disease that could be it couldn't be controlled in any other way it was pretty clear that was caused by infection at that point. And so if he could

do things that people wouldn't be able to do today. But even so you know he sent his paper showing describing his experiments to the Royal Society of London and the head of the Royal Society of London flatly rejected the paper and condemned him basically for saying things that were so at odds with what it was. Yeah but now you talk of prejudice and bigotry. Will I kind of cut you off but you also have to when the problem is that that today the use of vaccines in a preliminary way sort of in the pilot studies is very much dependent on sort of the mainstream thinking. And so if Jenner for example had those constraints he would have been able to do what he did he would have been ostracized for it. And so today I think there are these restrictions on what kinds of vaccines will be allowed to go through

clinical trials. And I think if you had a vaccine that was based on possible association between a pathogen and a chronic disease I don't think people would allow. The people who allow these preliminary trials to go through go ahead. I don't think they would allow that kind of trial to proceed without any strong evidence so I'm afraid we've got more restrictions today that's going to slow progress and it's slowing progress for good reason that the ideas that we're trying to protect the health of subjects in experimentation. So it just makes things a little bit harder also the other problem with this is that the experiments that Jenner did. So you know Jenner actually introduced smallpox into the boy that he supposedly had protected and actually actually had protected by introducing the material from the cow pox lesions. And people would allow that to be done either.

The other problem is that when you're dealing with chronic diseases the use of a vaccine isn't as feasible because you have to wait the vaccine as a as a way of determining whether the pathogen is the agent responsible for the chronic disease. It's not acceptable because you may have to wait for 30 or 40 years before the experiments finished. Right. With with smallpox I don't only have to wait for you know a year or if you're only using a few subjects we generally have to wait for a few weeks. We are entering into our last 15 minutes here and we have some other callers will try to get in as many people as we can and introduce Again our guest We're talking with Paul. He's professor of biology at Amherst College you'd like to read more on the subject. Look for his book plague time that's published by the Free Press. The number here in Champaign Urbana 3 3 3 9 4 5 5 toll free 800 to 2 2 9 4 5. Our next caller is in a band I believe on the line number four. Hello.

Oh thanks Jeff. Yeah I have two questions one is probably a short I was wondering OC when you talk about viruses aren't your fears to me I never really understood not being a student of biology. Why they weren't considered more akin to poison that had some sort of poisonous effect Consols replica reputation prophecies than living things and I just want to know if there were for a shorter answer as to why. Oh yeah the short answer is that the viruses cure self-replicating and they have the instructions for their own self replication built in. So that's the key thing that distinguishes things like poisons from living things. So a long time people thought the viruses weren't alive but that was I think largely. I mean it's a semantic issue but I think that it makes more sense to think of them as as living organisms that are just so trimmed down that basically their little packages of genetic material and protein that are designed to land on and in fact and live within take over

our cells. So they have a little bit of DNA RNA and DNA. Viruses have some DNA or RNA that encodes their own genetic information. Well anyway my real question I asked when you started out talking about that the kimi which had for so long latency period I was just wondering is it possible to give a quick. Yeah. Given that they couldn't use Koch's Postulates just how they came about how they came around to thinking that it you know or proving to their own other selves the folks of a community that you know entering the case this is about two decades ago that it was it was finally accepted. And basically what was done is they noticed that there was a tendency for the Leukemia to be occurring in very isolated areas a lot of this work was done in Japan. They

saw that they were looking for a virus that had had a geographic distribution that matched this funny geographic distribution of the adult T-cell leukemia and so they found that this virus this retrovirus is like a distant cousin of HIV it's called HTL the one they found that this retrovirus match that geographic distribution. And then they found that every person who had the adult T-cell leukemia had the virus. OK so those bits of information pieced together made people say you know there's no other explanation that makes any sense other than it's this virus that's causing eventually sometimes over time course of six or seven decades. The silicon you know. Well thanks for thanks for showing how it's difficult. The fellow Larry thanks for the call. Next a line to the. This is Bloomington. Hello. Caller their line too. I was told I was on line three. Well my apologies to your you're on right now. Go ahead. All right.

How do your ideas apply to prostate cancer. Well prostate cancer is a mystery. There have been some studies that indicate that prostate cancer may also have an infectious origin. There is geographic variation that looks like. The kind of variation in prostate cancer you'd expect from infectious causation. There have been some foreign proteins identified from prostate cancer tissue that are similar to those of foreign proteins that one finds in ovarian cancer tissue and other gynecological cancer tissue as well as in breast cancer tissue. And so this leads to lend some support for the idea that prostate cancer like some of the other cancers is caused by some pathogen and just not at all clear where the pathogen may be coming from. But I think that people haven't been

looking at this possibility very closely. Certainly not as closely as it is warranted. And I think maybe as people start looking more closely at the possibility what story will begin to make more sense and hopefully the right experiments will be done to find out. Whether there really are these foreign genetic elements inside the prostate cancer tissue you know and if they're there where are they coming from. Generally when you find these things they're result of viral infections who are picking up little snippets of viruses that are in the tile itself. Oh I had prostate cancer six years ago and that was interesting to me that you know I had to figure out how to own that and you're right it is a 5. Thank you very much. Let's go to champagne. This is line 3. Hello good morning. I think we would all agree that it's always better to better understand these things than not but I'm not sure that I entirely share

your optimism about it. How this will improve our condition as an example HIV. It was understood once it was recognized that it existed it was understood fairly early on how to prevent its spread. But most of the effort was spent in trying to develop a vaccine and trying to develop treatments rather than trying to educate people on the make condoms and their own needles available everywhere and in the different countries of the world that have used these two different two different approaches. The ones that have tried to use the obvious ways of preventing spread have been in general quite successful. On the one that have gone the other route are except for the very rich countries are sort of in a tank. And it seems to me that. I agree with you much more than you think. My point is that when we find

out that a pathogen is causing disease we don't know whether we're going to luck out and we're going to be able to control that pathogen or not some pathogens like HIV are going to be really tricky. And I've been writing in following the HIV experience really almost from the beginning of the research that implicated virus as a cause of AIDS. And one of the points I've been making is that this is a really tricky virus we're not likely to control this virus in the long run by a vaccine because of the characteristics of the virus. This is one that one for which we haven't lucked out on and we're not going to luck out on. It's I think it's worth doing research on vaccine development. I think it's worth definitely doing research on anti-viral drugs. But the one thing for control of AIDS that we know should work is getting the information out there about how dangerous unprotected

sex is and how dangerous it is to have more partners rather than fewer partners and then getting the information out there about the value of it. Using condoms and by getting this information out I think we're we know we could have some controlling effect it's not going to stop the virus in its tracks but it certainly is going to be something it's going to have a positive effect because the virus is so mutation prone. The hope that we're going to get a vaccine that's going to last for more than a few years is is pretty slim. I think we will get some vaccines against HIV but they're just not going to be having the same kind of effectiveness that the vaccines for example against measles has had for the vaccine against smallpox. Yeah but my point of the much more general one with respect to motor vehicle accidents it's something that has become familiar and accepted that when an automobile is provided when the manufacturer is provided

an automobile that corners better or brakes better or so forth that there's an adjustment that goes on where people drive faster and take more chances. So they're moving back toward I guess a sort of thought point. I think we see this in in health matters. Where it's known that even now hospital personnel don't wash their hands yet often enough. You know and the antibiotics that figure so strongly in your case where in the process of losing control you know so that we may be back to where we were in the 20s. You know but. Well a couple things One thing is sort of going from the last point to your earlier point. I don't put too much reliance on antibiotics because I think there are not a very good way of controlling the

spread of infectious diseases they're good for treating people who have disease that you can control it had antibiotics but as soon as you start trying to use them to control the organism in a population you generate get generate the antibiotic resistance problem. Now with regard to the idea that is soon as you start solving the problem people start getting lax that that is a big problem but I think the solution is not to try to solve the problem that this is the by using let's say a vaccine that will knock out the pathogens. I think the solution is to go ahead and generate the vaccine if it's going to. If you think it's going to work. But then also don't let up on the other control measures because we you know we have these three control measures we've got hygienic improvements we've got anti microbial and then we've got vaccines that have been the mainstay of medicine for the last. Well the last two centuries to the last 50 years depending on which combination of those things we're talking about. And I think it's important not to let

advancements in one of those take away from the effectiveness of others not to get lax and one of those just because we've got something else that could allow a person to become lax and I think that has happened in hospital environments because antibiotics seem to be this magic bullet. People started relying on antibiotics instead of keeping the hygienic measures at a high standard. And as a consequence I think we've seen a lot of problems in hospitals in those problems are are becoming amplified because. The antibiotic resistance that's been generated now people can't rely on the antibiotics in the same way that they were relied on 40 years ago and people have have gotten out of the habit of maintaining high hygienic standards. And so I think that the solution is to make sure that people follow all of those three appropriate guidelines for all of those three control measures that I mentioned before not to let's say let

up on the hygienic control measures just because you've got something like an antibiotic that you can use as a as a solution for a particular patient. We have just about two minutes and I would try to get one more caller in here in Urbana online one I'll have. Ask to be quick though. Here plan a difference between. Explain what crimes are I understand are infectious proteins but they don't irises. Their parents are a big mystery because everybody thought that all. Disease organisms all organisms had to have DNA RNA. And here you had a thing that was cause clearly causing terrible degenerative diseases that kill people making their brains into Swiss cheese essentially and it didn't seem to have any RNA or DNA in it. So it looks like what the right answer is that these are proteins that are essentially the same building blocks in the same sequence as proteins in our bodies. But they have a slightly different way of bending on each other. OK so that all of the protein has the same sequence it has a different

shape. In this approach the prion are associated with these diseases like Crisfield Yaacob disease or for mad cow disease. They when they get inside of a body they tend to change the confirmation of our version of the protein into that crayon version of the protein and then when they do that these prion confirmations tend to group together. And it's believed that that grouping together it's almost like a crystal vase and process is what eventually causes the destruction. In this case of neural tissue and then the downfall of the patient we're going to have to stop here sorry to say because we're just at the end of the time to anyone who is interested in the subject again I suggest you look at the book that we've been talking about the title the book is plague time is published by the free press and the author our guest Paul. He's

professor of biology at Amherst College Professor. Thanks very much for talking with us My pleasure.