CBS

Interview with Dr. Anthony Fauci

Posted on Dec 4, 2011 09:00pm


Dr. Anthony Fauci
Head of the National Institute of Allergy and Infectious Diseases at the N.I.H.

CBS CARES: In a capsule, what is the role of the National Institute of Allergy and Infectious Diseases in the fight against AIDS?

DR. FAUCI: Well, the National Institute of Allergy and Infectious Diseases is an institute of the National Institutes of Health that is responsible predominantly for basic and clinical research in the diagnosis, treatment and prevention of immunologic and infectious diseases. And since HIV/AIDS is one of the important global infectious diseases, our research endeavors are directed toward better understanding HIV and its disease-causing mechanisms developing diagnostics, therapies and tools of prevention, including an HIV vaccine. In other words, to push the envelope to the point where we have new and improved interventions against this terrible scourge. AIDS is one of the important mandates of our institute, and we've now had 23-plus years of experience in HIV/AIDS research.

CBS CARES: Did you develop the plan for the five-year, $15 billion, program to fight global AIDS?

DR. FAUCI: I was part of the team that the President put together to develop a plan for the treatment, care and prevention of HIV in developing nations, particularly in sub-Saharan Africa and the Caribbean. The program is now referred to as PEPFAR, or "The President's Emergency Plan For AIDS Relief."

CBS CARES: What is the goal of the PEPFAR program?

DR. FAUCI: The program is aimed at treating two million people with HIV/AIDS, preventing seven million HIV infections and ultimately caring for ten million people with HIV/AIDS.

CBS CARES: How do you decide which countries will receive the money and will any of it go towards research?

DR. FAUCI: None of it will go for research, because the research budget is a separate one. The entirety of the $15 billion in the president's program will go for treatment, for prevention and for care. It is a flexible number. But, in general, at least half of it will go to treatment; mainly the provision of anti-retroviral drugs to HIV infected individuals.

It's estimated that approximately 20 percent or so will go to prevention and the rest will go to care. That is a number that may change somewhat, not radically, as the program starts to mature. But the research money is not contained in that. Research money is a separate budget in addition to the $15 billion.

CBS CARES: How much goes into your separate research budget each year?

DR. FAUCI: Well, at the NIH, we spend approximately $2.9 billion a year in HIV/AIDS research.

CBS CARES: And, of that $2.9 billion, how much goes into research into vaccines and how much into research for better drugs to treat HIV?

DR. FAUCI: Well, I'd say right now, approximately 18 to 20 percent of the total goes into research on vaccines. And over 40 percent goes into therapy.

CBS CARES: Are there any HIV/AIDS vaccines in development now that, in your opinion, look promising?

DR. FAUCI: There are a number of candidate vaccines that are in development for HIV/AIDS. But the development of an HIV vaccine is going to be quite problematic, basically because of the fundamental nature of the virus and its ability to elude the immune system's capability of eliminating it or protecting the body against the virus.

There are a number of candidates that are at various stages of clinical trials. Some vaccines are in very early development. Some are in animal models. And there are some that we have already started to test in human safety studies. But I have to caution that the task of developing an HIV vaccine is going to be formidable. It is more formidable than most, if not all, of the vaccines that we've been challenged with developing over the years.

CBS CARES: You explained the virus' ability to evade the immune system. Can you please elaborate on how this and other complexities of the HIV virus make development of a vaccine so formidable?

DR. FAUCI: Well, a number of reasons. The nature of a protective immune response to HIV is still unclear. Because in a very, very unique manner, unlike virtually any other microbe with which we're familiar, the HIV virus has evolved in a way that the immune system finds it very difficult, if not impossible, to deal with the virus.

Let me give you an example. If you look at the history of infectious diseases, even some of the great killers of history: smallpox, polio, measles--the types of diseases that have actually fashioned civilization because of their impact--the body is usually able to ultimately handle those infections.

For example, only about 15 to 25 percent of people who get smallpox die. The other 75 to 85 percent do very well and their body completely eliminates the smallpox virus. The same holds true for polio. Only a very small percentage of people who get infected with polio are not able to handle it. But, for 90-plus percent of people, their own body ultimately protects them against the complications of these infections.

And then, once the body meets with the microbe, it develops an immunity, which protects it against subsequent challenge. That's just not the case with HIV. Of all of the tens of millions, actually a total of over 60 million people who have been infected with HIV worldwide, there are virtually no documented cases of people, once they've had established infection, who completely eliminate the virus from the body. So, for reasons that are still somewhat puzzling, the body is incapable of completely handling the HIV virus. And, since that's the case, it is very difficult to contrive and develop a way to present the virus in a manner, which would induce a protective immune response.

So it's a very difficult scientific issue that is clearly more challenging than the scientific issues with which we faced when we successfully developed other vaccines. In addition, the virus has an enormous capability of mutating and escaping the body's immune defenses.

CBS CARES: Despite the unique complexities of the HIV virus, do you believe that an effective HIV vaccine or cure is viable in our lifetime?

DR. FAUCI: Well, anything is possible. But there are many challenges associated with that goal. Let us take therapy first. We have excellent therapies that are capable of suppressing the virus to below detectable levels over an extended period of time, particularly in individuals who start therapy with a very potent anti-retroviral therapy that immediately turns off virus replication to avoid the emergence of resistance.

What we have not been able to do is to completely rid the body of virus. And that's what you, technically speaking, call a cure--when a virus is completely gone so that when you stop medicine, the virus does not rebound. That has been a goal that has eluded us up to this point. Likely because the virus has a way of inserting itself into the genome of cells that essentially protects it from getting eliminated by the anti-retroviral therapy.

So you have a constant reservoir of virus. Functionally, it might be considered equivalent to a cure if the virus remains suppressed while a patient receives therapy. But in the stricter sense, it is not because in most of the experiences with people taken off therapy, even those who have done very well, the virus ultimately rebounds. So I'm not sure whether we're going to be able to ultimately cure the virus. But we very likely may be able to control it for prolonged periods of time.

CBS CARES: Why are antibodies essentially unable to control the HIV virus? Is it that HIV compromises B cells and the quality of HIV antibodies is therefore defective? Or is it that the antibodies just don't work against this virus at all?

DR. FAUCI: Actually the virus does not predominantly infect B-cells. It predominantly infects CD4-positive T-cells. B-cells are indirectly negatively impacted by the virus. But the virus doesn't directly destroy or infect B-cells. The issue is that the B-cells have trouble recognizing the components of the virus for which you would develop what's called a protective response.

When you vaccinate someone or when you get infected, the microbe is presenting itself to the immune system in a way that the immune system recognizes the important elements of the microbe and makes an immune response, both an antibody response and a cellular response, to ultimately contain the microbe. The components of HIV that the body's immune system would have to recognize in order to mount an effective immune response are virtually, in many respects, masked and unable to be seen by the immune system. So a person may get infected with HIV, but the immune system doesn't recognize the virus in a manner that elicits an ultimate protective immune response. So a successful HIV vaccine would require our doing something that is even better than what the body itself can do.

CBS CARES: In the press release for your presentation at the 2004 World AIDS Conference in Bangkok, you seemed to describe HIV as an immune activating disease?

DR. FAUCI: Right.

CBS CARES: Has there been a change in your thinking in that, until now, it seems that HIV has been viewed--at least in the U.S.--as an immune suppressive disease?

DR. FAUCI: No. Actually it's both and it's somewhat paradoxical. The ultimate effect of HIV is to suppress the body's immune system by destroying a very critical cellular component of the immune system, namely the CD4-positive T-cells.

But, one of the ways that HIV disrupts the immune system is by creating a state of aberrant or inappropriate immune activation in which the entire immune system is turned on. But because it's turned on in an inappropriate fashion, the ultimate effect turns out to be immuno-suppression as opposed to an appropriate specific immunological response.

CBS CARES: So, it's essentially an issue of timeline…some of the time HIV causes an overactive immune system and other times it results in immune suppression?

DR. FAUCI: It's a question of degree of activation and persistence of activation. When the immune system functions normally, it recognizes a foreign antigen. That could be a microbe. That could be a tumor. It could be something like that. Any of those things that are recognized as foreign.

And it ultimately turns itself on for a limited period of time, makes the appropriate specific response and then reverts back to its baseline, relatively resting state. That's the immune system functioning normally. If the constant bombardment of the virus turns on the immune system in a manner that's highly intense and highly persistent, it doesn't give the immune system room to respond in a normal manner to the stimulus that you're trying to protect against.

CBS CARES: Well, to the extent that HIV overactivates the immune system, do you see any role in the future for treating HIV patients in the U.S. with immune modulating or immune suppressive drugs like prednisone or cyclosporine?

DR. FAUCI: Well, those drugs have been tried, in various degrees, in animal models and even in human studies. So far, they have not been successful. However, I still think it's an open question that should be pursued as to whether or not we can selectively tone down the aberrant immune activation to the point where you get a beneficial effect, but not so much so that you suppress the immune system to the point of making matters even worse.

So you're walking a fine, delicate line when you're talking about immunosuppression or blunting immune activation as a therapeutic modality. It is something that, in principle, has some basis, but must be explored with great caution. And there are some clinical trials looking now at ways to blunt the aberrancy of the immune response without blunting the important components of the immune response that are necessary to contain the virus.

CBS CARES: We understand that NIH is experimenting with use of interleukin-2 in patients as a way to stimulate production of CD4 immune cells to replace those killed by HIV?

DR. FAUCI: That is correct.

CBS CARES: Since, as you explained earlier, the HIV virus has an affinity for attacking and destroying CD4 cells, is it possible that, by creating more CD4 cells through use of interleukin-2, the ultimate outcome could, ironically, be acceleration of HIV disease and, consequently, a weakened immune system?

DR. FAUCI: Conceivably, but that's the reason why interleukin-2 is generally administered simultaneously with medications that block the ability of the virus to replicate. So that you could get the best of both worlds where you're amplifying the immune system without necessarily turning on the virus replication. Because the virus replication is being held in check by the simultaneous administration of anti-retroviral therapy.

CBS CARES: Are these replacement CD4 immune cells, produced through use of interleukin, qualitatively as good as natural CD4 cells or is there a functional difference?

DR. FAUCI: Well, thus far, the ones that are produced appear to be functionally normal. The open question is would you have what we call the repertoire of the CD4 responses. Namely, the breadth of recognition capabilities. Is that going to ultimately be restored? And that's something that's under active study right now. But by all other measures, the CD4 cells appear to be relatively normal.

CBS CARES: NIH seems to have shown great interest in testing genetic profiles of HIV-positive patients through HLA typing. Can you please explain what HLA typing means and could this advance knowledge and treatment of HIV? For example, is it possible that new drugs or vaccines could be developed from what you learn?

DR. FAUCI: Well, it's probably more related to the nature of the immune response. An HLA typing is sort of a genetic profile. There are certain antigens that define what make me different from you from a genetic standpoint that relates to the immune system. HLA are molecules on cells that are important in the recognition and the ultimate triggering of an immune response.

There are certain genetic profiles that are more prone to one type of an immune response against a particular microbe versus another. And that's the reason why people with different HLA backgrounds have different responses and different propensities to a number of different diseases. What investigators are trying to do is to try and learn if there is any association between certain HLA profiles and the ability to contain the virus so that that could serve as an insight into how one might control the virus through immunological means, even in those people who don't possess a particular genetic background. So it's really a window into understanding the nature of a relatively protective immune response.

CBS CARES: Do some of the rare people, whose immune systems prevent the HIV virus from progressing for many years--so-called "long term non-progressors"--have any specific HLA or other genetic subtypes that could explain their relative immunity?

DR. FAUCI: Well, there's a very, very small group of truly long term non-progressors--people who, without any therapy, have virtually undetectable virus for years and years and years. And they seem to fall into one HLA subtype. But this is a very, very rare situation--less than one percent of HIV-infected individuals.

That gives us some insight that there very well is an immunological component to the control of virus by this very small subset of patients. And the question is how we utilize that knowledge to understand how we can induce the immune system to make a comparable degree of that type of protection, even in those people who don't have the proper immunological or genetic background.

CBS CARES: Is the idea to take the immune protective HLA type in long-term progressors and try to create a drug or vaccine that would mimic the protection for others?

DR. FAUCI: Not necessarily a drug. But what component of the immune system is more effectively stimulated in association with this particular HLA background. And to try and use that as insight. It has probably less to do with designing a drug than it does with creating a vaccine.

CBS CARES: On another aspect of genetics, do scientists view the Human Genome Project as potentially a key to finding a vaccine or cure for AIDS?

DR. FAUCI: I think the Human Genome Project transcends all disciplines. And the more you know about the genetic makeup of the human, the more insight you might get into things like responsiveness to certain antigens. And so it certainly could be helpful. I don't think it's the only key to where we want to go. But as in most disciplines, understanding the complicated genetic makeup of humans is certainly an important addition to our scientific knowledge.

CBS CARES: We understand that recent research at NIAID shows that human cells, similar to those of some plants and insects, are capable of silencing an essential part of viruses' genetic makeup. How does this work and could this so-called RNA "silencing" process lead to novel types of HIV drugs?

DR. FAUCI: There is an emerging view that prior to organisms developing protein- and cell-based immunities, which are the two major components that humans currently use to fight pathogens, a more ancient RNA-based immunity might have been widely used. Plants and insects do not have our more highly evolved protein- and cell-based immunities; instead, they use an RNA-immunity to either degrade or prevent the translation of mRNAs encoded by invading pathogens. A question is whether RNA-based immunity still exists in humans as we evolve more sophisticated defenses. Previous studies have shown that RNA-immunity can be artificially provoked in human cells to defend against viruses. Recent findings at NIAID indicate that HIV-1 can, in fact, naturally evoke an RNA-defense when it infects human cells. Our overall understanding indicates that RNA-based immunity could be employed to ward off HIV-1; however, many details remain to be worked out before we know if this route can yield a useful HIV-drug.

CBS CARES: Can we turn to the subject of natural killer cells, which we see you've written on and spoken about? As we understand it, natural killer cells are essentially the frontline soldiers in the body's immune defense against a range of serious diseases?

DR. FAUCI: Correct.

CBS CARES: In addition to killing CD4 immune cells, does HIV kill these natural killer cells?

DR. FAUCI: Well, it doesn't necessarily destroy them. It creates an environment in which they naturally die at a higher rate. We call that "apoptosis." But natural killer cells do not directly get infected with HIV.

CBS CARES: It seems that, to track the state of an HIV positive person's immune system, the main focus is on monitoring the number of his or her CD4 immune cells, because CD4's are a primary target for the virus. But, you're also saying that natural killer cells are important in fighting serious diseases and do die at a faster rate in HIV infected people. Do you foresee that doctors will someday routinely monitor levels of natural killer cells in HIV patients and boost them if they're below normal?

DR. FAUCI: I think it's still unclear right now as to what the role of natural killer, NK, cells is in immediate and long-term protection against HIV. This is something that our lab and a number of labs throughout the world are looking at. I think it's too early to say what particular role NK cells play in the control of HIV replication.

Knowing what the fundamental nature and basis and function of NK cells are, I certainly would not be surprised if they make some contribution very likely during the course of very early infection before you actually mount a specific immune response. Because, of course, NK cells are part of the innate immune system which is much more of a rapid early response with less specificity than the adaptive immune response that comes a little bit later. But, it is much more specific than the initial, innate immune response. A lot of labs are trying to determine what the relative role of NK cells is in immune protection against HIV.

CBS CARES: Back on the issue of CD4 immune cells, the focus in HIV treatment seems to be on the quantity of CD4 cells in a patient, not on their quality or functionality. Could qualitative problems with CD4 cells explain why some HIV positive people feel sicker at higher CD4 levels or develop opportunistic infections and cancers usually associated with much lower CD4 levels?

DR. FAUCI: Well, it's unclear. The immune system in its response is multifaceted and heterogeneous even though CD4 cells are a major player in all of this. Certainly it is likely that the functional integrity of any given number of CD4 cells would play a major role in differences between two separate people who, on the surface, seem to have quantitatively the same number of CD4 cells.

And yet there's a lot of biological variability from person to person that could explain how they handle things like opportunistic infection. So, it's probably a complexity of issues, including what the relative effect of the circulating virus is on the functional capability of CD4-positive T-cells. It is not something that can be easily answered because of the complexity of what goes into protecting you against the things like opportunistic infections and Kaposi's sarcoma.

CBS CARES: There's been a rapid increase in the number of HIV infections that are resistant to many or all of the anti-retroviral drugs. What percent of new infections in the United States are drug-resistant to some extent or completely? Why is it happening and what new drugs are in existence or development to overcome the problem of drug resistance?

DR. FAUCI: Well, drug resistance is a predictable natural problem for any situation in which you are effectively treating against the microbe. Because microbes have the innate genetic capability of averting what we as humans do to try and eliminate them by the capability of rapid replication and mutation.

So it is an expected phenomenon to have increasing numbers of resistance strains as you treat groups of people, particularly large groups of people as we're doing with HIV for prolonged periods of time. The way around that is to continue a robust pipeline of new drugs. To develop drugs not only against targets for which you already have drugs, but also drugs against newer targets to help to circumvent the ultimate emergence of resistance.

This is the reason why we have drugs now against the binding and ultimate fusion of HIV with cells. Those are relatively new compared to the reverse transcriptase and protease inhibitors. There is a lot of work going on now to develop integrase inhibitors, which prevent HIV from integrating itself into the host cell's genome. These are the kinds of things that are in the HIV drug pipeline that, in fact, will ultimately be used to obviate some of these problems we have with the naturally predictable emergence of resistance.

CBS CARES: Is the drug Fuzeon an example of this type of drug?

DR. FAUCI: Yes.

CBS CARES: Fuzeon seems to be a very complicated drug to store and inject. Do you expect that it will come in a tablet form at some point in the near future?

DR. FAUCI: Well, the company is working on that. I don't think I can comment on what it's ultimately going to be.

CBS CARES: We understand that the NIH is doing what you call the "7-7" study--cycling HIV patients on and off their drugs on alternate weeks?

DR. FAUCI: Right.

CBS CARES: HIV doctors seem to get upset with their patients if they miss even one dose of HIV medication because non-adherence can cause drug resistance. Is it possible that on and off cycling of HIV drugs could cause HIV in that patient to become drug resistant?

DR. FAUCI: Well, the cycling would be relevant and important only if the virus does not rebound. Earlier studies have shown that it takes about two weeks before the virus starts to rebound. So if you have the interval between interruptions short enough so that the virus does not rebound, then you have the possibility of getting along with less drugs.

The critical issue is if the virus starts to rebound within that period, then it's not going to work. Ultimately, if you cyclically have rebounding of virus replication, you have a higher risk of resistance. And that's the reason why this is not at all recommended for anyone until clinical trials prove or disprove the feasibility of this approach. So this is not something that's ready for "primetime" at all and might not ever be. That's the reason why the clinical studies need to be done carefully.

CBS CARES: Would cycling on and off with antiretroviral drugs such as nevirapine or efavirenz, which are a mutation or two away from resistance, be even riskier?

DR. FAUCI: Those questions are being asked in carefully conducted clinical trials and the only way to know the answer is to test it. Again, just to underscore, this is not something that should be done by anyone until the clinical trials are finished.

CBS CARES: What is the average life expectancy of someone who is diagnosed with HIV today in the United States?

DR. FAUCI: It's a moving target. I don't think I can definitively give you a life expectancy because we're in the middle of the whole evolution of this increasing life span. Back in the old days where there wasn't good therapy, from the time you had an AIDS-defining illness, the life span was a mean of about 26 weeks.

I have patients now who I've been following for 15 years who are doing extraordinarily well. You can't put a number on it until you have many, many more years of observation. But it certainly is enormously expanded from what it was years ago.

CBS CARES: What are the worst side effects for patients on HIV drugs?

DR. FAUCI: There are a number of side effects. Number one are metabolic effects. There are organ-specific as well as hypersensitivity effects. It just depends on a particular drug. It's a whole combination of anything ranging from metabolic effects to things like liver damage, kidney damage, skin problems, hypersensitivity problems. And that's why the treatment of an HIV-infected individual needs to be monitored very carefully by physicians.

CBS CARES: What would you say to young people today who say "it's not a big deal to get HIV and that there are effective drugs to control the disease"?

DR. FAUCI: That's a very, very, very risky mindset and quite inappropriate. HIV infection is not something to take lightly, so everyone should be concerned about protecting themselves from HIV infection and preventing it from being transmitted to others if they are infected.

Despite the fact that we have good drugs, the burden of HIV disease can be terrible and can lead to death despite the medical advances. So it is important to tell that to people who think HIV/AIDS is something they don't need to worry about.

CBS CARES: Why are infection rates in the U.S. not going down?

DR. FAUCI: I think it's probably because of the pervasive perception in society that HIV is a problem that we now have under control. And it's unfortunate that over the last ten-plus years, even more, we've had a steady annual rate of about 40,000 new infections.

The demography shifts. You know, it doesn't necessarily mean in the same populations. Right now, for example, in inner city minorities, we have young women who are getting infected from partners they don't realize are infected and these women, themselves, are monogamous.

We also have young gay men who don't have the experience of seeing so many of their friends and colleagues dying of a bad disease because they weren't around in the early '80s, so there's a lot of misperception about risk. And, unfortunately, that misperception is leading to a sustained and unacceptably high level of infection in this country.

CBS CARES: Why is the goal of successful antiretroviral therapy to suppress HIV viral load in plasma to less than 50 copies per cubic milliliter? Why was this threshold of 50 chosen?

DR. FAUCI: You want the viral load to be undetectable. Fifty is an arbitrary cut-off, which is the range of detection of the viral load tests in question.

CBS CARES: Why not a goal to reduce viral load to zero? Wouldn't the less than 50 viral copies that remain be the most drug resistant because they have survived the onslaught of the drugs and could they cause problems at a later point?

DR. FAUCI: The reason it isn't zero is because you can't measure zero. That's the point. The tests are not that sensitive, so that's the reason why they say less than 50. I mean, you would like to get it to be zero, but given the current, readily available viral load tests, you can't get down that low.

There's also no evidence that people who are being followed with less than 50 viral copies for years and years do develop resistance. In fact, there's some evidence to indicate that if you keep them below that threshold of 50, they do just fine. And they don't spontaneously develop resistance unless the virus percolates up to levels that are much higher than that.

CBS CARES: The FDA requires that HIV-1, Group M antibody tests--so called "ELISA tests"--be tested against the major Group M subtypes, not against all its subtypes. Do you think the diagnostic tests in the United States have kept pace with the constant genetic mutations of HIV and increases in infections by genetically divergent subtypes such as the "Non B's"?

DR. FAUCI: Well, they're two different things. The genetic mutation of the B subtype is going to be picked up by the ELISA test. The genetic mutation has more to do with resistance than our ability to detect it with a diagnostic test. There doesn't seem to be a significant amount of other subtypes slipping through the cracks.

The FDA is continually monitoring whether antibodies to different genetic subtypes could slip through. And if it turns out that we do have an influx of cases that get beyond our ability to diagnose them, for example in screening blood, then I am certain that they will then institute the appropriate tests to fill those gaps.

CBS CARES: How far back can the first human blood sample with HIV be traced?

DR. FAUCI: That's debatable. People say the late-'50s, early-'60s, but that's something that is continually on and off the table. It certainly is earlier than the first recognition in the late-'70s and early-'80s.

CBS CARES: Have we learned any lessons from the fact that HIV was around for decades, spreading and infecting humans, but remaining unknown and undiagnosable? For example, are any steps now being taken to ensure that the next HIV is detected and intercepted before it spreads widely and becomes an epidemic?

DR. FAUCI: Well, if you look now at the capabilities of the World Health Organization that partners with countries, including the Centers for Disease Control in the United States, surveillance for diseases now is considerably better than it was 20 years ago. There's no question about that. The surveillance of emerging and unexplained diseases worldwide is much keener than it was years ago.

CBS CARES: Wangari Maathai, the Kenyan woman who recently won the Nobel Peace Prize has said that HIV did not jump from chimpanzees and monkeys to humans. She says that HIV was created by scientists as a biological weapon to perpetrate genocide. What is your response to that?

DR. FAUCI: I think it's unfortunate that she made that statement because, obviously, that's not true. I think she somehow dampens the impact of many good things she's done by making an uninformed statement like that.

CBS CARES: Is it fair to say that this a good time for infectious diseases, because there are relatively few antiviral drugs in medicine, antibiotics have become less effective due to misuse and there are constantly new and challenging viral and bacterial infections with which the human immune system struggles to cope?

DR. FAUCI: Well, I wouldn't word it that way. I would say that it's important to have infectious disease experts because infectious diseases continue to be an extraordinary challenge to global health.

CBS CARES: What makes you most optimistic and what worries you the most today about the HIV pandemic?

DR. FAUCI: Well, what makes me optimistic is the continued excellent science that's developing new drugs and the pipelines as well as our better understanding about the immune system and its relationship to what we can do vis-à-vis the development of a vaccine. Even though, as I mentioned, this is quite a difficult problem.

I feel good about the fact that we're finally getting drugs to the people in developing nations who need them through a variety of programs--the Global Fund, the President's Emergency Plan for AIDS Relief, a variety of bilateral programs. So we are finally, after so many years, getting treatment and care to the people who need it the most. That's what I feel good about.

What I feel badly about is that we still have major threats to our global civilization. The situation in Asia is a time bomb. I would hope that we don't have the explosion of cases in Asia, particularly China and India and other Asian countries, that we've had in sub-Saharan Africa. So we really need to try as much as we can as a global community to prevent that from happening.

CBS CARES: Why did you decide to specialize in infectious diseases?

DR. FAUCI: I've been excited about infectious disease from the time I was a medical student because, well, first of all, they are very serious diseases. They have global impact. They're diseases that are eminently preventable and treatable, unlike some diseases.

So, the application of good science to development of important countermeasures for prevention and treatment gives you an extraordinary amount of opportunity to have a very important positive impact on the health of the world because of the large burden of infectious diseases. Infectious diseases, even today with all our vaccines and therapies, are the second leading cause of death worldwide and the first leading cause of death among young people.

And they are the largest cause of disability years, associated with disease burden. So the importance of infectious diseases is undisputable. And as scientists and clinicians, we have an extraordinary opportunity to do something that will have an important global impact, worldwide. I came to the NIH and got involved in a very good infectious disease program after my training as a medical intern and resident and I have been enthralled with the sub-specialty ever since.

CBS CARES: Thank you so much for giving us all this time. The last question is: is there any question we didn't ask, but which you think we should have?

DR. FAUCI: No, I think we covered the subject very extensively.

CBS CARES: Well, many thanks again.