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CIAO DATE: 12/99
Lessons Learned from the AIDS Epidemic
March 23, 1999, Hong Kong
Introduction
I’m going to speak to you about AIDS, which stands for Acquired Immunodeficiency Syndrome. It is a disease caused by a virus that destroys a critical part of the immune system. It was first recognized in 1981 when I was first finishing up medical training. Today, arguably, we view it as the plague of the millennium. The cause of AIDS is shown here. This is a high magnification of HIV, Human Immune Virus, or the AIDS virus. You can see that it is actually extremely small; you cannot even see it with a regular microscope. This image is visualized via an electron microscope. This virus has spread throughout the world and it is causing what we would call a pandemic, that is, every region of the world is now affected. And the numbers are truly frightening.
I’m just going to use numbers. Cumulatively, we now know that forty-seven million individuals throughout the world have been infected since the beginning of this epidemic. Approximately, fourteen million have already died. This leaves us with approximately thirty-three million individuals throughout the world living with HIV infection. Even though I will tell you about some therapeutic progress, most of these people are going to die within a five to ten year period.
Here are the breakdowns for the total infection. As I said there are over 33 million individuals with the virus, and as you can see here, 22.5 million cases in sub-Saharan Africa. Approximately two out of three of the world’s cases occur in that region and we believe that is the origin of AIDS, or HIV. This region is obviously so severely affected now that it is really difficult for us to imagine the magnitude of the African epidemic.
AIDS Worldwide
There are four countries, for example, Zimbabwe, where one in four of their citizens carry HIV. There are villages where one in three or one in two of the population are infected and are likely to die in the near future. Many of the countries in sub-Saharan Africa have one in ten of its citizens infected. And if you go to countries such as South Africa, and go to pre-natal clinics where pregnant women go for check-ups, it is not unusual to have a high percentage—thirty, forty or even fifty percent—of the pregnant women carrying HIV. It is known that many of them will then pass on this lethal virus to their offspring.
In fact, the epidemic is so severe in sub-Saharan Africa that life expectancy or longevity which has been steadily increasing over the past several decades in Africa to a level beyond fifty years old, is now headed back down. Life expectancy in Africa because of the AIDS epidemic is now less than fifty years old. That, of course, is devastating the continent and you can imagine what it is doing—the kind of social, economic impact it has on the societies there. HIV is not like certain other diseases affecting the elderly population. It is affecting people who are sexually active—typically in the 20s, 30s and 40s—people who are in the prime of their productive years. The impact on the continent will be felt in many different ways besides the personal ones.
But aside from this situation, you can also see in North America, primarily in the United States, there are about one million or slightly less, and quite importantly, over a million, in South America. Western Europe has about half of the United States cases, and very importantly, this number is deceiving for Eastern Europe because it shows about a quarter of a million cases. Most of the cases have occurred only in the past few years. So the epidemic in the former Soviet Union and many of the former Eastern Block countries is also extremely severe because of increasing drug use and increasing prostitution.
For the audience here, you must notice the numbers shown here. It is clear that South Asia and Southeast Asia are very severely affected with nearly seven million cases as of last year. The bulk of this actually occurs in India, where the World Health Organization (WHO) officials estimate that approximately four to five million cases have occurred. As a single country, India has the most people with HIV infection. Frighteningly, most of the cases have occurred only in the past few years. The trajectory for that epidemic is extremely sharp, so that it will quickly worsen over the next few years given that no effective measures are now in place to deal with this burgeoning epidemic.
Of course, we also know that a substantial portion of that occurred in Indo-China. We all know the situation in Thailand is grave, with approximately a million individuals infected in a small country. The situation in neighboring countries such as Cambodia, Myanmar and so forth, are no better. Those places, aside from some of the measures implemented in Thailand recently, have no effective way of dealing with the current epidemic. The situation is likely to get much worse here. You also notice for East Asia and the Pacific region, approximately half a million cases. I am sad to say that most of these cases are now accounted for by China.
Rate of New Infections
Let’s think about new infections. What I showed you on the previous slide is what we have in terms of prevalence of HIV infections. But if we think about new infections per year, and for the year 1998 we have almost six million new infections, and remember these people—if they are not treated, they are doomed to die of a slow and miserable disease probably over a five to ten year period. Now, this may be difficult to appreciate, but that breaks down to sixteen thousand cases per day. As we sit here, that number is a bit numbing—sixteen thousand cases per day, and these people are contracting a lethal virus. Now put it in more graphic form, that is akin to fifty 747 jumbo jets—full of people—going down each day.
With those kind of numbers, you quickly realize the extent of the urgency we are facing with this particular epidemic. You also wonder why there is such indifference and such complacency when we are faced with such a challenge. It is important to remember that even though the sub-Saharan epidemic is still extremely severe, the number in this region of the world is increasing. Because of the huge population in Asia which will account for forty plus percent of the world’s population in about five years time, is going to have more new infections per year in Asia than in Africa. This is where the battle line is being drawn with AIDS and HIV.
China and Hong Kong
Now, I do want to talk a little bit about China because now we are sitting here in Hong Kong. I have been visiting China every year since the early 1990s and meeting with scientists there as well as health officials, and I can recall the days when discussions with ministers of health talked about numbers less than one thousand total cases. Initially, there were a number of foreigners in Beijing and Shanghai—the larger cities with HIV infection. These cases were found in the mid-to-late 1980s.
But by the late 1980s, it was known that a number of Chinese residing in Yunnan province were coming down with HIV infection. They reside in two counties at the border with Myanmar. These are Chinese minorities who go back and forth and are virtually indistinguishable in terms of their backgrounds, with many of the natives on the Burma side. It was clear that that the epidemic was related to intravenous drug use of heroin, and in fact, were largely limited to young kids and young adults.
Heroin, in this region near the Golden Triangle, is so cheap that kids could get this and inject it into their veins even if they do not have proper needles and syringes. It is clear that people are very creative when they want to be—you could use a sharp bamboo tip, put some heroin in that, and it would inject straight into the vein. People shared such devices with one another, so it’s not surprising that the epidemic spread very quickly among drug users who also happened to have sex. Therefore, the epidemic propagated in to the sexual partners of such drug users and then later onto their offspring.
Very quickly, the epidemic blossomed, and like the situation in Africa, in Thailand and in India, it quickly spread by the routes of communication or transport—truck routes, rail lines and so forth. It’s clear that this epidemic has disseminated to the heartland of China. Many of you probably will be surprised to hear that provinces such as Anhui, Hubei, Henan and so on, have lots of reports of HIV infection. Even the extreme northwest, Xinjiang province, has an epidemic situation. It is truly sad to know that this epidemic, despite all the lessons learned in Africa, in Thailand, and in the United States, China is repeating the same mistakes.
Now, the official number is probably around two hundred thousand cases, but the more reliable number is probably four to five hundred thousand cases as estimated by the World Health Organization. With such a huge population at risk, this is surely going to get much, much worse before it will improve. This is the kind of internal threat to China that it hasn’t really fully realized. Yes, intellectually, I speak with the Minister of Health and many of the scientists and doctors in the health ministry, yet the actions lack any measure of urgency. If you have so many of your citizens at risk, it is very difficult to understand why there is persistent denial of the problem.
Lessons From the U.S.
While I am certainly critical about the relative inactivity to prevent HIV infection, I wanted to show you what actually transpired in the U.S. throughout the decades of the 80s and 90s and these mistakes were already made by a “developed country.” Two years after the initial recognition of AIDS, the Centers for Disease Control (CDC) in the U.S. reported approximately a thousand cases. These thousand cases were represented by a few yellow dots here in New York, in Chicago, in Los Angeles, San Francisco and Texas. Only a few dots.
You can see that only two years later, the caseload increased by ten fold and the dots are much more apparent along the two seaboards and in Texas. Again, just a few more years later, the caseload increased another ten fold and now the epidemic is abundantly clear. Throughout this period, the very top of the American leadership—the President uttered the words “AIDS” only twice. You can see by 1995 there were half a million cases, and by today, the number is probably around a million. A lethal disease is allowed to spread in this fashion when this is totally a preventable disease.
It is transmitted, we know, by sex and by blood contact. It is not casually transmitted via handshakes, sharing of some utensils, etc. It is not transmitted easily. It is a preventable disease, and the situation is getting worse. I think it is important that all of us help spread the message about AIDS; everybody should know something about this epidemic. It now rivals malaria and tuberculosis as the major killers around the world. Sitting in this comfortable room in Hong Kong, it is difficult to appreciate that in fact, most of the people in the world die from infections. Not cancer, not heart attacks, but infections. Now the top three are tuberculosis, malaria and HIV. HIV is the one that is continuing to grow with time.
It is very bad of me to speak of so much gloom and doom. In the second portion, I would like to convey to you that there is actually a reason for hope. That is, hope based on scientific progress. That isn’t to say the epidemic is going to be controlled. No—in fact, it is not going to be controlled for a long time and this epidemic will be with us for the remainder of our lives and probably with our children and our grandchildren. It will be here for several generations even if we come up with very effective drugs and vaccines.
The General Structure of the AIDS Virus
What I wanted to tell you is that so much has been learned about this virus that it gives us a real reason for hope. This is just a schematic diagram—it’s not a real picture—of the virus. I said, it’s actually really small—it’s for people who know what one hundred nanometers are—that’s the size. It’s very compact, and is a very small virus. It’s wrapped in lipids, so it’s got a fatty envelope and it has various proteins embedded on the surface. These proteins allow the virus to find its target. This is important because the virus is very strategic. It goes for a certain cell in our immune system. Inside, it packs various structural proteins and these proteins wrap the genetic material of the virus which exists in the form of RNA into a tight cord. The virus carries a few enzymes to do its business.
That is sort of the general structure. As time passes, we know more and more about some the details of these structural features. Ever since the mid-1980s, we’ve pretty much known the entire genome of the virus. It’s very small; it’s ten thousand bases. It’s extremely small compared to billions and billions of bases in our genome. We know how the genetic information within this virus is organized; we know this will make the structural proteins, this will make the enzymes, this will make the protein that sits on the surface. We know that it has a number of other things that help regulate the virus up and down. I won’t get into the technical details here, but for a very small virus, it actually is very clever to pack in many other genes to regulate it one way or another to cause more virus replication. We also know a great deal about the various steps that the virus goes through in its replication cycle, or the life cycle of the virus. Again, the details are not important; I just want to give you a flavor of what science has uncovered.
How HIV Works
HIV finds the right cell through very specific interactions at the cell surface. It doesn’t infect just any cell in the body; it infects cells in the body that express two molecules. One is something we call CD4 and the other is what we call chemokine receptor. What they are, are not important. In fact, HIV just hones in on these two molecules and docks with these two: one for CD4 and second with the other one. After that, it throws a harpoon onto the cell surface and brings the cell in and fuses with the cell. It injects its internal contents into the cell. From there, the genome RNA gets made into DNA.
The genetic flow is in reverse—it goes from RNA into DNA when typically it’s the other way around. This DNA has a way of moving into the center of the cell and interestingly, the virus has a mechanism to stitch that DNA into the chromosome of the cell—that is, the chromosome of the host. You can see the virus becomes part of the person, and this is why curing HIV is so difficult because the virus basically becomes part of the infected person. HIV has these special enzymes that would allow it to convert from RNA to DNA or to stitch the DNA into the chromosome.
From there, it just makes more of itself. It makes RNA, proteins and interestingly, these things have a way of spontaneously bubbling up to the cell surface. Viral particles just butt out one at a time or a multitude at a time, and they come out like this. In the final stages it does another thing: it has to take the proteins that it has made—these proteins are huge proteins—and then just chop them into small pieces. To do that it requires an enzyme called protease.
Protease is nothing but a chemical scissor. It knows exactly where to cut, so it will cut the large pieces into the proper small pieces, and they will fold into a mature progeny viral particle. This infected cell, you can see, makes about ten thousand viral progenies. From the infection of a single cell, HIV will make ten thousand, and you can see how this might spread throughout the body of an infected person.
That cell, which happened to be infected by the virus, turns out to be a critical cell in our immune system. We call it a lymphocyte—a CD4 T-Cell. It is an essential orchestrator of much of our immune cells. The cells have number of mechanisms to fight off infections, and maybe even cancer cells. Many of them—I won’t go into what they are—but this whole process is orchestrated by this T4 lymphocyte, and that is the target for HIV. HIV infects this cell and gradually depletes that cell over a long period of time, so that it causes the collapse of the entire immune system. HIV per se may not kill. It simply wipes out the immune system so that the person, because of the collapse of the immune system, is susceptible to infections that are normally warded off.
New Drives to Fight HIV and the AIDS Virus
I also wanted to give you an idea of the kind of progress that has been made that translates into real differences for patients who are infected with HIV. I come back to this slide simply to say if we know the various steps in the viral life cycle, and we understand which ones are essential to the virus, it would be logical to try to block those steps. If we know that this process could be cut somewhere—here or here—then we could potentially block the continual replication of this virus.
One step is actually right here, as the virus is trying to go from RNA to DNA; we could actually develop inhibitors to see if we could interrupt that process. Starting from the mid-1980s until the mid-1990s, a number of drugs—this is only a small representation—have been developed and here are their chemical structures. What they really are is not that important. What these drugs do is that they trick the virus.
Here, this is again just a cartoon showing you the genome of HIV, which is in the form of RNA, and as it uses its enzyme to copy this RNA into DNA, you see this DNA growing. These are the building blocks of our normal DNA, but if you have drugs like this that mimic the building blocks and fit into this process but lack the proper connections for this DNA to elongate, to grow, then you could block and interrupt this process. That is what these drugs do in fact.
However, these drugs did not turn out to be all that powerful. They help lower the virus by a few fold, up to five fold, and to prolong the lives of patients by generally a few months to a year. It did not make a dramatic impact, although it was very helpful. Until new inhibitors came, and here, at the very end here, I spent a little bit of time telling you about this chemical scissor. If this chemical scissor needs to do its thing to cut the proteins from large to small, if somehow you gum up the scissor, so that this process cannot occur, then the virus would be dead.
Developments in the Early 90s
Throughout the late 80s, many basic scientists have invested a lot of time to understand the structural aspect of this protease or the chemical scissor. By the late 80s we knew the three dimensional structure with great resolution. It’s actually quite pretty and elegant. You can see it’s a symmetrical structure, so the left and right sides are a mirror image.
Basically, HIV makes one part and the other part is another identical molecule; they come together as twins to form a single enzyme—a business molecule. This is actually the cutting side, and this has been understood for some time. The big protein would actually come and sit in this groove and then HIV protease would do the cutting. Because of this understanding of the structure, it made sense that if we fit a chemical into this groove, you could block the cutting process.
By design, working with a number of pharmaceutical companies, we began to test these in the early-90s and particularly, this one and this one, but many others were developed. You can see structurally, they are not the same. But these things could be tightly fitted into that cavity within the protease. These form very tight bindings to the protease, and we understand how this might occur. Once it gets in there, it won’t come out. So the scissor is “gummed up” permanently.
We worked on these things in the laboratory throughout the early 1990s, and by 1994, realized that they were very powerful and we could take them into the clinic to give them to patients. To our great amazement, we saw that the amount of virus just drops—plummets in each case—every single case, by ten, a hundred and sometimes a thousand fold. It was already evident that these drugs are more powerful than drugs we have previously used.
Understanding the AIDS Virus
At about this time, we also began to understand what the virus is actually doing. I won’t tell you how we came to these conclusions, but I will share with you perhaps a description of what HIV is doing in the body of an infected person. It allows me to tell you that we know the magnitude of HIV growth in infected individuals. These are viral particles; they come out of the infected cells. I told you one single infected cell could make up to ten thousand progenies. What we learned is that this process of continuing production of virus and re-infection of the cell is a non-stop process. It goes on for the duration of infection in an infected person. It goes on every single day, and each day it goes through one cycle.
The number of viral particles that are made each day is quite shocking. It’s generally ten billion to a trillion viral particles, destroying in that process about a billion of these very important CD4 cells in the body of an infected person. That is the kind of onslaught that goes on day after day for many, many years, sometimes a decade. It’s actually quite amazing that an infected person is capable of enduring that kind of onslaught for so long. But once you get this picture, you realize that even though a person is infected and is clinically well, in that person, this process is going on continuously at a rapid click. Therefore, it would be wise to intervene and block that process from churning and churning.
It also led us to an important realization and this has to do with the fact that if you have a huge number of viruses that are made each day, they will try to undergo a new infection. The problem is that as HIV tries to undergo new infections, it makes mistakes. You could say—well, that’s very stupid for the virus. It makes mistakes and it cannot fix mistakes. It’s almost like a grade school child writing out something—it makes spelling mistakes, grammar mistakes, and does not go back and proofread.
For us, when we copy our DNA, when our cells divide, that process has high fidelity—it does not make too many mistakes. Even if a mistake occurs, we have a mechanism to fix it. But the virus doesn’t. You could say, “many of its babies, its progenies will be dead” and in fact, that is the case. But, some of its babies will look sufficiently different and because of evolution, or Darwinian evolution, it allows the virus to change, and to adapt to the environment and to resist the drugs that we give to attack the virus. It changes so quickly that it doesn’t matter if you kill off 99.9% of the virus as long as 0.1% survives, it will then repopulate very quickly because of the dynamics.
It is a very good evolutionary strategy for the virus—and very bad for us. That immediately—I won’t go through the technical features and calculations—predicted that if we use the drugs I told you about one at a time, HIV simply mutates and becomes resistant. It takes only a few days or a few weeks for the virus to do that. Immediately we realized if we attack the virus one at a time, we would lose—it would simply jump over each hurdle we put in its way. But this information also presented to us a strategy. If you wreck one hurdle for the virus one at a time, it’s not going to work. But if you wrecked a huge hurdle a single time and asked the virus to jump over it, you would find it statistically unlikely.
That is the fundamental basis for the chemotherapy we use today—the “cocktail” therapy, or the combination therapy. I actually hate the term “cocktail.” And I hate even more people calling me “Mr. Cocktail.” But that is the fundamental basis for our therapy. Today, it is routine to have this kind of results—to give three or four of the drugs that I told you about—together, erecting barriers so high that HIV is unable to overcome it. The virus drops in a matter of a few weeks to a few months, to levels that are no longer detectable. We’ve been keeping it that way for some years now, not in every single case, but in a huge majority of the cases.
Where We Are Today
Allowing us to control HIV replication—halting the destructive process to the immune system—allows the immune system to slowly rebuild itself. As the immune system improves, these people move out of the danger zone for catching these other infections, and therefore, this is associated with tremendous clinical benefit. This is why if we look at AIDS mortality in the U.S., there has been a tremendous turn around. The AIDS associated mortality has gone up steadily ever since 1981 until 1995, 1996, 1997, and 1998 is going to be further decreased. It is because of the development of the protease inhibitors and their use in combination with some of the older be it drugs used three or four years ago.
If you say, “That’s the United States, what about elsewhere?” It’s the same in Western Europe where these drugs are available. I’m not aware of the local statistics for Hong Kong, but for Taiwan, this phenomenon is also observed where the government basically buys the drug and provides it to the needed population. While this is a tremendous improvement on what we had before, we do not have a cure for this. When you treat with these drugs, the HIV is essentially gone. If we take a hundred sections of the lymph nodes, 95% would be totally clean but in a few of the sections, a little bit of virus remains. We have not cured the infection. This little bit is not doing much damage, but the problem is that it is preventing us from stopping our therapy. If we were to stop, this would serve as an opportunity for the virus to rekindle that highly active process. It is keeping us on these therapies that are expensive—probably an excess of US$10,000 per year just for medication alone. There are also complicated, sometimes patients have to take them multiple times a day, and up to twenty pills a day. And of course, they are associated with side effects. We would like to get rid of the residual virus some day, and that is an area of active research for us—to see if we can find a way to purge or eradicate, so that we can finish up with the cure. That has not been achieved yet.
Let me return to my final slide, which I have shown before, to say that if we keep in mind the tremendous progress made for patients in North America, Western Europe and in select countries in Asia, that is not where the infection is. The infection—90% occurs in developing countries: sub-Saharan Africa, in South East Asia. So you can immediately see that while these scientific advances are impressive and the therapies are great, they are not going to have an impact when we take a few steps back and look at the big picture.
So we have to use preventive measures to deal with this epidemic. The preventive measures depend on education and implementing anything that would help to lower the spread of HIV infection. And education—knowledge—is power. Much more needs to be done along that line. As scientists, however, our task on the effort of prevention is to come up with a vaccine as we have done with many other viruses. Smallpox has been wiped off the face of the planet because of smallpox vaccines. Polio is near the point of eradication because of an effective vaccine. We need to come up with the same, but the obstacles are rather daunting for coming up with the AIDS vaccine, and I don’t have time to go into that. That is why we need to deal with this global epidemic even though working on a cure is still meaningful, and will be certainly very hopeful for those who are already infected. In the long run, we have to come up with a vaccine. Let me end there, and if time permits, I’m happy to entertain comments and questions. Thank you.
Questions and Answers
Question 1: I would like to take this opportunity to thank Dr. Ho for what I consider as a very informative talk on facts, warning, hope and vision. I think he has brought to this Hong Kong community a lot of new insights. My question is, as you already mentioned, the cocktail treatment is a very effective one but very expensive. It looks ironic that while the developing countries or the rather poorer countries have the majority of the disease, they probably could not afford the treatment. I wonder what Dr. Ho’s thoughts on this were. My second question to him as a scientist is that how long does he think it will take before a vaccine is developed?
David Ho: Both are very tough questions. I think it certainly tragic for me, one who has helped with the effort of developing some of these drugs and implementing their use, to realize that that effort is only benefiting a minority—in fact probably, in the order of five percent of the infected population throughout the world. But it is also part of reality that these medications are not affordable in sub-Saharan Africa. It is the kind of inequality that exists in every aspect of life. We think about it for AIDS, because AIDS is so severe there, but it’s also true if you have diabetes or heart disease, or cancer; in sub-Saharan Africa, you are not going to get properly treated. So this is just part of the inequality that exists—the sort of “North-South problem”. And I don’t know what to do about it. I think, in fact, many of the pharmaceutical companies are eager to help out. They have made their profit, probably out of guilt, and they want to help out, yet on such a large scale, they cannot do it. But on a smaller scale, you could go into South Africa, or Thailand, and say, “We want to help selectively to block mother-to-infant transmission.” The drug companies are willing to donate drugs for that effort; perhaps an U.N. organization could provide some of the infrastructure funding. So that you could selectively benefit a segment of the population and help protect another generation. Such measures are being looked at very seriously together with the industry to see if that might happen.
Second question on the vaccine: this virus has been difficult. Traditional approaches of making a vaccine for polio, for example, you grow the virus up, you kill it, you give it, and that was the vaccine. Or through modern technology, as we have now for hepatitis B—you make the surface protein by using what we call recombinant techniques. You make just the protein and you put that protein in the arm of the person and that person, after three shots, is immunized and is protected against hepatitis B. If you adopt the same strategies for HIV, they don’t work. They don’t work for a lot of reasons—this virus is a stealth virus. Its surface is so well shielded—for those of you like science fiction—it’s got a force that shields it. It also is capable of changing so it is a moving target. There are other obstacles. Development of a vaccine is challenging but in animal experiments, we all realize it is do-able. We just have to come up with a strategy that is safe, and could be widely implemented. There is no point developing a vaccine for Western Europe or the U.S. This is an effort intended for the whole world, and that is not easy so far. Very boldly, President Clinton has declared that we shall have a vaccine by the year 2007. I hope that he is right.
Question 2: Is there some evidence in Africa or Asia of people who are naturally immune to the disease, and is that going to be any help in finding a cure or a vaccine?
David Ho: There are many aspects of AIDS that I did not talk about today. Three years ago, we realized that some people were repeatedly exposed to the virus, and not infected. You could say, “Oh, that’s good luck.” But then we went on and showed that some of their cells—these CD4 T cells—are not infectable by the HIV in the test tube. And that is very unusual. And it turns out, after further genetic work on such cases, that these two docking sites on the cell surface that the virus must engage to penetrate, some of these people are missing one of those molecules—the one I wrote as CCR5 chemokine receptor. Interestingly, these people have inherited the gene for this molecule as defective forms. The gene is truncated and this defect only exists in Northern Europeans and not in blacks, not in Asians. And so a tiny minority of the Caucasian population is, actually not 100%, but quite well protected.
Question 3: Your second to last slide which showed the residue disease—in spite of your intensive drug therapy—have you done anything with the herbal medicine, especially with the Chinese herbal medicines which are very well known for improving the natural immunity and the natural defense mechanism?
David Ho: We have not done anything in that setting. In fact, western medicine does not have too many drugs that could enhance immunity. Chinese traditional medicine—it is claimed—that many of them would enhance immunity. So it may be a logical place to try. In fact, that little dot that I showed you is a T-Cell that carries the virus for a long time, and we could facilitate the eradication of that population if we could turn the T-Cell on. This is something that we call amino enhancers or amino modulators. In western medicine, we don’t have anything that will do that very effectively without causing toxicity. I, unfortunately, do not know a sufficient amount about traditional medicine, so it is hard for me to comment. Some years ago, we tried to see if herbal extracts would have anti-HIV activity, and there are plenty that do, in fact. It is just that none of them have been sufficiently purified for the kind of analysis we think that ought to be done. It is a promising area; I certainly don’t want to dismiss it. But unfortunately, the research infrastructure in the U.S is such that it is set up to support traditional things, and non-traditional things are unlikely to be funded. If that is to take place, it would probably be logical for places in China to pursue that.
Question 4: You mentioned the need for education—could you comment on common misconceptions about how it is transmitted, and how it is not transmitted?
David Ho: Well, I think most educated people in developed countries know something about this. As I said, it is transmitted by close, close contact—sexual contact or sharing of blood, and blood products. It is not casually transmitted, and there are a lot of people who think this might be passed if you happen to shake hands with an infected person or be in the same room and breathe the same air. Those are common misconceptions and they are very counterproductive to what needs to be achieved. They create irrational fear; they isolate the patients; they create the kind of denial that exists at the very top of our governments. If this were an international problem that killed off ten citizens per day, not to mention 16,000, everyone would spring into action. It is hard for me to understand the complacency or the indifference, and this applies to everywhere, not just the Chinese government or the Indian government or the Thai government. It has happened in the U.S, and still there is a level of resistance at the top of the U.S government. It is perceived to be a disease that effects only the fringe of society, and that is wrong. Viruses do not know arbitrary boundaries created by man. They will just go and attack any susceptible cell. So those misconceptions are very damaging to what we need to do. That is why I said knowledge is power. You not only need to understand how the virus is transmitted, how the transmission could be prevented, but you also need to get an appreciation of the magnitude of this problem and develop a sense of urgency.
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