 |
|
AIDS: The Elusive Vaccine
After twenty-three years of intense research into the human immunodeficiency
virus (HIV), together with the accumulated experience of more than twenty
million deaths from the in-fection worldwide, there is still no prospect of
a vaccine to prevent AIDS. Is the discovery of a vaccine simply a matter of
time? Or has this virus presented scientists with a hitherto underestimated,
perhaps even impossible, challenge?
The International AIDS Vaccine Initiative (IAVI), the world's largest single
organization devoted to finding an AIDS vac-cine, has argued that the
obsta-cles to progress are clear and resolvable—lack of political commitment
and inadequate scientific resources. With offices in New York, Amsterdam,
Nairobi, and New Delhi, it has invested $100 million in the search for a
vaccine. At the Bangkok AIDS conference held in July of this year, Seth
Berkley, IAVI's president, argued that "only a vaccine can end the
epidemic," that "a vaccine is achievable," and that spending on vaccine
research must double to $1.3 billion annually in order to find it. "The
world is inching toward a vaccine, when we should be making strides," he
said. The present situation was little short of "a global disgrace."
But contrary to the predictions and promises of most AIDS experts, the signs
are that a vaccine to prevent HIV infection will not be found for, at the
very least, several decades to come—if at all. Those responsible for
carrying on the global fight against AIDS do not accept this grim outlook,
at least publicly. Yet it is a conclusion, based on all the evidence
gathered so far, which increasingly defies rebuttal. Until the gravity of
this scientific failure is openly acknowledged, a serious debate about how
to end HIV's lethal grip on some of the poorest and most vulnerable human
populations in the world cannot take place.
1.The holy grail of AIDS prevention is a single-dose, safe, affordable, oral
vaccine that gives lifelong protection against all subtypes of HIV. The
first hurdle facing vaccine designers, therefore, is dealing with the
extraordinary genetic complexity of the HIV epidemic.
HIV exists as two strains—HIV-1, which dominates the epidemic, and HIV-2,
which is largely confined to West Africa. So far, at least ten different
patterns of HIV-1 infection have been identified. These patterns reflect
particular geographic and genetic profiles of viral spread. For example,
HIV-1 subtype B (there are nine genetic subtypes) is the common form of the
virus in North America and Western Europe. India, by contrast, is under
threat from HIV-1 subtype C. In Africa, where some two thirds of those with
HIV now live (about 25 million people) and where there were three million
new infections in 2003 alone, the situation is more diverse. Southern and
eastern regions of the continent face a predominantly HIV-1 subtype C
epidemic. Central Africa sees a highly mixed picture—HIV-1 subtypes A, D, F,
G, H, J, and K. The implications of these differences for vaccine
development remain uncertain. The best guess is that the genetic complexity
of HIV will influence the effectiveness of any tested vaccine.
There are also over a dozen virus variants, called circulating recombinant
forms, whose genomes have a structure that lies in between those of known
subtypes. They also contribute to the difficulty of creating a
one-size-fits-all vaccine. At present, scientists do not know if each
subtype and every variant will need its own specific vaccine. It may well be
that they will.
Worse still, a given subtype of the virus does not stay the same. HIV is
continually evolving. The ingenuity of the virus in adapting to prevailing
pressures in its environment—such as the existence of a vaccine that
triggers an attempt by the human body to eradicate it—is owing to an enzyme
called reverse transcriptase. This enzyme is essential for viral replication
but it makes mistakes as it goes about its work. These mistakes, together
with an extremely high rate of virus production, help HIV to produce an
enormous family of genetically varied offspring.
Even if a vaccine were available, these different forms of HIV would almost
certainly allow some of the virus to "escape" from any protective immune
response that the human body mounted against it after vaccination. Some of
these randomly generated "escape mutants," as they are called, would then be
selected for survival in succeeding generations of the virus, since they
would possess the advantage of being "fitter"—avoiding the body's immune
response—than their nonmutated counterparts.
--------------------------------------------------------------------------------
These problems become easier to understand when one considers how a vaccine
to prevent HIV infection would have to work if it was to produce what
experts call sterilizing immunity—that is, complete protection from
infection. The normal immune system has two ways of responding to infection.
The first depends on the antibodies we all produce in our bodies. These
large molecules bind to the virus particle and neutralize it, preventing HIV
from going on to infect human cells. There are two critically important
proteins on the surface of HIV-1, which are called gp120 and gp41. They are
the means by which the virus enters human cells and they are the main
targets of the neutralizing antibodies. The difficulty is that crucial parts
of these surface molecules are hidden from the attacking antibodies. Such
resilient viral topography, together with several molecular tricks that
enable HIV to evade human defenses, severely weakens the body's immune
response. Antibodies alone are therefore very unlikely to protect us from
HIV.
The second response of the immune system involves not the production of
antibodies but the rallying of cells to combat infection. There are two
types of blood cell that are involved in an effective immune response to
HIV— CD4+ and CD8+ T-lymphocytes, cells that develop within the thymus
gland. The CD4+ cell is HIV's primary target. It is this cell type that is
hit hardest by the virus, causing the typical immunodeficiency that
characterizes AIDS. CD8+ cells—also called cytotoxic T-lymphocytes (CTLs)—matter
because, among other actions, they kill cells that become infected with HIV.
They are usually assisted in their task by CD4+ lymphocytes, which are,
appropriately, also known as T-helper cells. This mopping-up operation has
the potential to damp down the damage that HIV can do to the body.
Once a person is infected, a contest begins between the virus, which is
trying to establish a foothold in the body, and the cellular immune
response, which is trying to stop the virus from doing so. A vaccine should
tip the balance of this contest in favor of the immune system by increasing
the numbers of CD4+ and CD8+ cells that are poised to swing into action if
HIV gains entry to the body at some point in the future.
In truth, a vaccine that strengthens this kind of cell-mediated immunity
would probably not prevent infection. It would likely slow the rate at which
the virus took over and destroyed the body's immune system; and such control
of viral replication would be immensely helpful if it could be achieved.
Indeed, the notion of a CTL-based HIV vaccine is surprisingly popular in
view of the technical difficulties of producing it. David Garber and Mark
Feinberg, respected HIV investigators at the Emory Vaccine Research Center
in Atlanta, write:
If widely implemented, such vaccines may have a significant impact on
improving the quality and length of life for HIV-infected individuals, while
at the same time reducing the rate at which HIV continues to spread
throughout the human population.[1]
But despite the importance of these T-cell responses against HIV, especially
in the acute phase of infection, they ultimately fail to control HIV's
effects. Nobody knows exactly why. It is clear that a CTL-based HIV vaccine
would have to improve upon the immune response that is induced by natural
infection. This is a huge demand to put on a vaccine and it is far from
clear that it could be achieved. Vaccines of this kind would face the
additional problem of overcoming HIV's remarkable genetic diversity.
The sum total of our knowledge about the genetics, biology, and geographical
distribution of HIV indicates that vaccine scientists may have met their
match in this adaptable foe. The reality seems to be that a vaccine against
AIDS is becoming little more than a pipe dream.
2.Despite these sobering concerns, the rhetoric surrounding AIDS vaccines
continues unabated. At the Bangkok AIDS conference this July, for example,
IAVI's publication Scientific Blueprint 2004 strongly advocated the
acceleration of global efforts to discover an AIDS vaccine. It deplored the
fact that less than one percent of all health product research and
development spending is currently allocated to finding a vaccine to prevent
HIV infection. But IAVI is less clear about how the new money it is
demanding—$650 million—should be spent.
The IAVI's position is troubling. It raises the expectation that if only
enough money were thrown into AIDS vaccine research, then a solution would
appear in the not too distant future. But the implication that money is by
itself the answer is wrong. The difficulties facing vaccine researchers are
far more complex.
Meanwhile, in June of this year, at its Sea Island Summit, the G8 nations
endorsed the creation of a new consortium—the Global HIV Vaccine Enterprise.
It remains unclear exactly what this new organization will do.[2] Such lack
of clarity did not stop Lee Jong-wook, the World Health Organization's
director-general, from calling it "a new political and financial dimension"
to HIV vaccine development. It is neither political nor financial.
There is talk of greater scientific collaboration, along the lines of the
Human Genome Project. The words "strategy" and "synergy" are often mentioned
in documents discussing the enterprise, words that certainly indicate good
intent. For example, the UK government's program for tackling HIV and AIDS
in the developing world, which was published shortly after the Bangkok
meeting, makes the unqualified comment that the enterprise "will accelerate
research and development of an effective vaccine." But so far the enterprise
has no formal organization, no overall leadership, and no new money for
research —just a $15 million start-up grant to create a "virtual center,"
which will likely be located in an already existing American institution.
One reason why scientists created IAVI in 1996 and lobbied for the Global
HIV Vaccine Enterprise in 2004 was a sense of collective failure to deliver
on earlier commitments to develop a vaccine. Since 1987, there have been
over eighty trials of thirty different candidate AIDS vaccines. All have
proven to be disappointing. The results of the world's first two large-scale
vaccine studies were reported in 2003. Again, both failed to show any
benefit. Given these early disappointments, what can we expect from HIV
vaccine research in the future?
The perfect vaccine would be a live but inactive or attenuated version of
HIV—that is, a virus which has been disabled and cannot cause disease. This
type of vaccine would resemble those already used to prevent polio, measles,
and yellow fever. Indeed, the vaccine that eradicated smallpox was a live
but attenuated form of the smallpox virus. But the great anxiety about a
live attenuated HIV vaccine is that it would be unsafe. Since there is a
small possibility that the vaccine could cause the infection it was trying
to prevent, the risk, as of now, is simply too great to take.
The alternative low-risk strategy is to use a vaccine made up of dead
protein. For example, if preparations of the proteins gp120 or gp41 were
injected, there would be no opportunity, even accidentally, to cause HIV
infection. The proteins generate an immune response within the human body
that scientists had once hoped would resemble the immune response generated
by HIV itself. This approach was the basis for the two failed trials of
gp120-based vaccines in the US and Thailand, reported last year.
--------------------------------------------------------------------------------
Between these two unworkable extremes, there is a multiplicity of new
technologies that are now being tested. The idea behind most of these
approaches is to deliver a vaccine consisting of protein or DNA using a live
virus that is not HIV. This live virus acts as a vehicle—called a vector—to
carry and enhance the effectiveness of the vaccine. More importantly,
instead of trying merely to generate antibodies to bits of HIV, such as
gp120, the intention behind using a live virus is to activate the T-cells
that are used by the immune system as one of its main responses to
infection. These vaccines aim to produce cytotoxic T-lymphocytes that will
kill HIV-infected cells. But already this approach represents an important
concession by vaccine scientists. For instead of pursuing the goal of
preventing HIV from infecting the body (achieving immunity through a process
of sterilization), a vaccine strategy based upon cell-mediated mechanisms
acknowledges that the best that can be hoped for is a vaccine to suppress an
already established infection.
One such CTL vaccine is currently being studied in Thailand. Sixteen
thousand men and women are being recruited for a three-year trial of a gp120
vaccine whose effects will, it is hoped, be boosted by a viral vec-tor
called canarypox. Four injections of the vaccine will be given. Few
scientists expect this study to yield a breakthrough. Indeed, many experts
believe that the Thai trial is misjudged, even unethical. The vaccine vector
is a weak stimulant of the immune response. One part of the vaccine is
completely ineffective. And there is no evidence that the vaccine will do
what it is supposed to do—namely, provoke protective antibody and cellular
responses to HIV. In view of these deep concerns, plans for undertaking a
similar study in the US have been rejected. Scientists simply do not believe
that the evidence supporting the vaccine's efficacy is sufficient to justify
such a large-scale investigation among human beings. The final results of
the Thai trial will not be available until 2008 or 2009. It is a long time
to wait for failure.
Later this year another viral vector, this time using a virus called
adenovirus, will enter advanced clinical testing. Scientists see this study
as a useful step in proving that the concept of a viral vector works, but
nobody expects this vaccine to prevent HIV infection.
A further approach is to introduce into the human body naked DNA— HIV genes
that are sown into a circle of harmless bacterial DNA. DNA vaccines were
initially hailed as a revolution in vaccinology. That exuberance was based
on very preliminary findings in mice. This premature enthusiasm has more
recently given way to caution as the technology has gradually been
transferred to humans, with only limited short-term success.[3] Finally,
since HIV usually enters the body through mucosal surfaces—the vagina and
rectum—augmenting an immune response at these portals of entry by using what
scientists call mucosal AIDS vaccines might be an additional way to improve
protection against infection. Several vaccine candidates exist, but human
studies have only recently begun. Experts disagree about whether this
technique will offer any advantages over more conventional vaccines.
--------------------------------------------------------------------------------
Currently, there are twenty-two candidate AIDS vaccines undergoing human
trials. Although this number has risen sharply—there were only seven
vaccines being tested in 2002—they do not exhibit a conceptual leap in
overcoming the obstacles to a vaccine I have outlined. Still, it is fair to
say that the science of why vaccines fail is progressing at a rapid rate.
But here lies a moral rather than a scientific predicament for doctors
looking after people with AIDS.
When a clinical trial of a vaccine begins, scientists hope that the study
will add useful information about the efficacy of the vaccine and its
mechanism of action. Ideally, they start from a position of
neutrality—scientists call it the "uncertainty principle"—about whether the
technology being tested will work or not. They might hope that it will, but
they honestly do not know for sure. Yet the pace of HIV vaccine research is
now growing so swiftly that the scientific goal of conducting and completing
a clinical trial may be threatened by a higher ethical obligation—to inform
those taking part in the study that the original scientific basis for the
research may have been modified by later work. Or it may even have been
completely discredited. At this point, the trial should be stopped —and
stopped quickly. No human experiment ought to continue if its scientific
justification has been undermined.
Many scientists believe that the Thai HIV vaccine trial, which had recruited
over 2,500 of its projected 16,000 participants by June 2004, has no chance
of success.[4] Yet the investigators overseeing the study (who include
American scientists), the local Thai institutional review boards, and the
Thai Ministry of Health have all remained silent—at least on the record. Off
the record, one member of the study's safety committee smiled anxiously when
I asked him about the propriety of continuing this trial. "Good question,"
he shot back. It seems that what is unacceptable in the US is now somehow
acceptable in Thailand. This smacks of astonishing ethical relativism.
IAVI is correct, therefore, to describe the present landscape of vaccine
research as a "tragedy." But it is tragic not because insufficient time or
resources have been brought to bear on the problem. A vast amount of very
good scientific work has been completed on the biology of HIV and the
various avenues open for vaccine development. Rather, what is tragic is the
inclination of the HIV vaccine community to portray the future of vaccine
research in such a misleadingly hopeful light—to support research at any
moral cost.
3.What is the alternative to a vaccine? There are two widely heard answers
to this question, which unnecessarily compete with each other—expanded
access to treatment and a great many proven and yet-to-be-proven preventive
measures. Lee Jong-wook's ambitious target of treating three million people
with anti-HIV drugs by the end of 2005—his so-called "3 by 5" program—is so
far falling very short of expectations. Although twice as many people are
now being treated with drugs than in 2002, the present number—about
440,000—is still 60,000 short of WHO's projections. The agency admits that
this situation is "disappointing." Some reports have gone further, drawing
attention to experts who accuse WHO of "sloppy" statistics in their claims
for even limited success.[5]
Prevention efforts have largely rested on the formula of A-B-C—abstinence
from sex, being faithful, and using condoms. While these messages are
important, for many people they are very difficult or impossible to put into
practice. The most disturbing aspect of the HIV epidemic today is the way in
which it is spreading among women. Women make up almost two thirds of
fifteen-to-twenty-four-year-olds living with HIV—they are now three times
more likely to become infected than young men. Over three quarters of these
HIV-positive women live in sub-Saharan Africa—in South Africa, one in four
becomes infected with HIV by the time she is twenty-two years old. In 1985,
35 percent of those with HIV were women. By 2003, that proportion had
climbed to 48 percent. In sub-Saharan Africa it is 57 percent. Even in North
America, the prevalence of HIV among women rose by 5 percent between 2001
and 2003—the highest increase among women in any part of the world today.
Why is this?
Partly, it is because of lack of knowledge about the virus and its
transmission. Partly, it is because women are more vulnerable to infection
than men. For example, the risk of acquiring HIV for men engaging in peno-vaginal
sex is 3 per 10,000 contacts. For women, it is 20 per 10,000 contacts, a
sevenfold increased likelihood of infection. But more importantly it is
because of the kind of relationships that women have with men. Many women
are simply not in a position to negotiate A or B or C with their male
partners. Older men will frequently have sex with younger women who are not
in a position to refuse them. Migration of men in the pursuit of work or war
encourages multiple sexual partners and unsafe sexual practices. And the
concurrent epidemic of sexually transmitted infections only increases the
risk of acquiring HIV still further. These facts are frequently ignored by
many Western policymakers seeking simple, all-encompassing solutions.
What might help women most of all is a personal method that they could use
to protect themselves from infection. If a condom is neither available nor
practicable, could a substance applied to the vagina which destroys the
virus—a microbicide—be the answer? Some scientists believe so. Dr. Zeda
Rosenberg, who leads the International Partnership for Microbicides, argued
in Bangkok that a microbicide to protect women from HIV could be available
within five years. One hopes that this prediction does not go the way of
those made about vaccines.
--------------------------------------------------------------------------------
It is not surprising that the debate about the best means to combat the
global AIDS epidemic has also become a domestic political issue in the US.
The President's Emergency Plan for AIDS Relief (PEPFAR) will invest $15
billion in AIDS treatment, prevention, and care programs over five years.
Fifteen nations have been chosen to be beneficiaries of PEPFAR.[6] The plan
is being administered by Randall L. Tobias, the former president and chief
executive officer of Eli Lilly.
Bush's cash commitment has been welcomed by people in the AIDS community.
But many are disappointed that the US is not intending to provide greater
support to the only international financing organization devoted to building
AIDS prevention programs in the countries that need them most. This Global
Fund to Fight AIDS, Tuberculosis, and Malaria was created in 2002, having
been endorsed by the UN, together with the leaders of G8 and African
nations. After only thirty months it had spent over $3 billion on almost
three hundred two-year programs in nearly 130 nations.[7] Of the US
government's $15 billion, only $1 billion is being channeled to the Global
Fund over five years.
To have made such a relatively small investment is to have missed an
important opportunity. The Global Fund was created specifically to meet the
needs of those most at risk of AIDS. Duplicating its efforts with an
exclusively American initiative will waste time and resources. There is also
a suspicion that PEPFAR will allow the US government to pursue its own
narrow ideological agenda—for example, by supporting faith-based abstinence
efforts rather than programs for reducing harm through campaigns for needle
exchange and condom distribution.
While speaking about his plans in Philadelphia in June of this year, Bush
underlined the "moral message" of PEPFAR. He said that "we need to tell our
children that abstinence is the only certain way to avoid contacting HIV."
John Kerry has responded by promising to double the amount government spends
on AIDS and to work more closely with multilateral organizations such as the
Global Fund. AIDS has become a deeply partisan issue in an election year.
Amid this polarized debate, vaccines are barely mentioned. In UNAIDS's
two-hundred-page global report on the epidemic, released in July, vaccines
received only a cursory reference. Elsewhere, however, UNAIDS reiterated
IAVI's conclusion that investment in vaccine research is falling well below
what is needed. In Bangkok, some delegates deplored the failure to subject
the lack of progress toward an AIDS vaccine to critical scrutiny.[8] José
Esparza, a leading HIV vaccine advocate and an adviser on vaccines to the
Bill and Melinda Gates Foundation, was frank in saying "we were wrong" to
think that a vaccine could be discovered easily.[9]
And yet the notion of a vaccine has not been entirely forgotten. A new kind
of vaccine has been proposed, one that many observers believe has had a
profound effect in a country long threatened by HIV. In describing how
Uganda responded to AIDS in the 1980s, President Yoweri Museveni argued that
"with no medical vaccine in sight, behavioral change had to be our social
vaccine and this was within our modest means." He gave this comparison:
Individual behavior and personal responsibility, based on knowledge, will be
our best protection against AIDS and other future epidemics. In Uganda we
managed to bring the HIV sero-prevalence from 18.6 percent to 6.1 percent
using just a social vaccine, a reduction close to 70 percent.... I am told
by the medical scientists that a medical vaccine with 80 percent efficacy is
considered a very good vaccine.
As Helen Epstein has recently pointed out, however, the relatively stable
family environment in Uganda is significantly different from more violent
and migratory conditions seen elsewhere in Africa:
Ugandans are more likely to live near their families and know their
neighbors, and this probably enabled a more compassionate, open response to
AIDS and a more rapid acceptance of the idea that trust and mutual fidelity
were possible. The far more brutal history of southern Africa had the
opposite effect. It weakened people's sense of trust and undermined
relationships between men and women. Many experts contend that
sexual-behavior change in Africa is complicated because women's fear of
abusive partners inhibits private discussions of sex, condom use and
HIV.[10]
In view of the different social conditions in different regions it is often
far from clear just what a social vaccine would consist of and how men and
women would accept it. In Bangkok, the Thai government pledged its
commitment to sex education in schools and behavior change, explicitly
endorsing the notion of a social vaccine.[11] But one wonders just how
efficiently particular programs of sex education in schools will change
behavior. To find the best means of preventing HIV, we need evidence on a
country-by-country basis about what methods do and do not work in different
social environments. For most parts of the world, that evidence does not
exist. What is perhaps striking is the way in which the word "vaccine,"
embodying a particular idea that remains unfulfilled in one context, is
being applied in another setting. It seems that the concept of a vaccine is
too powerful, its connotations offer too much hope, to let technical failure
in the laboratory extinguish its meaning for communities.
Six days of talking in Bangkok made it clear that the world should plan its
response to AIDS on the assumption that there will be no vaccine, in the
ordinary sense of the word, to stop the spread of HIV. Microbicides might
eventually be part of the answer, as might A-B-C. But our long-term defense
requires a deeper understanding of the conditions in which AIDS is
transmitted, and how they might be changed. The most important recent
revelation about HIV-AIDS—but the one most difficult to act on because it
does not lend itself to a simple technical fix—is the central position of
women in the epidemic.[12] For it is the relations of women with men in
different societies that will determine the course of this plague.
AIDS is increasingly affecting women; and marriage—in which there can be
frequent episodes of male violence and sex with multiple partners— has
become a serious and significant risk factor for acquiring HIV.[13] In
Uganda, for all its relative progress, rape and domestic abuse have been
important factors in sustaining the epidemic.[14] Is it too much to hope
that the searing catastrophe of AIDS may have put before women and men an
issue that they can use to confront male violence, exploitation, and stigma?
By 2010 there will be 25 million children orphaned because of AIDS. This is
a human atrocity that women and men must contend with together—and without
the help of a vaccine.
Notes
[1] See David A. Garber and Mark B. Feinberg, "AIDS Vaccine Development: The
Long and Winding Road," AIDS Reviews, Vol. 5, No. 3 (2003), pp. 131–139.
[2] The idea for a Global HIV Vaccine Enterprise was first raised in 2003 by
leading representatives of the Bill and Melinda Gates Foundation, the
National Institutes of Health, the Centers for Disease Control and
Prevention, UNAIDS, and IAVI. The proposal gave details about structures and
standardizations for laboratories, clinical trials, and manufacturing. There
was an implicit assumption, nowhere argued cogently, that the science will
one day deliver a vaccine. See Richard D. Klausner and colleagues, "The Need
for a Global HIV Vaccine Enterprise," Science, Vol. 300 (2003), pp.
2036–2039.
[3] See Marie J. Estcourt and colleagues, "DNA Vaccines Against Human
Immunodeficiency Virus Type 1," Immunological Reviews, Vol. 199 (2004), pp.
144–155.
[4] In January 2004, a group of respected investigators wrote to Science
voicing their concern about the wisdom of the US government in sponsoring
the Thai vaccine trial. They did not believe that the vaccine had any
prospect of success. They suggested that "one price for repetitive failure
could be crucial erosion of confidence by the public and politicians in our
capability of developing an effective AIDS vaccine collectively." See Dennis
R. Burton and colleagues, "A Sound Rationale Needed for Phase III HIV-1
Vaccine Trials," Science, Vol. 303 (2004), p. 316.
[5] See Lawrence K. Altman, "Ambitious HIV Plan Slowed by Obstacles,"
International Herald Tribune, July 12, 2004, p. 3.
[6] These countries are Botswana, Côte d'Ivoire, Ethiopia, Guyana, Haiti,
Kenya, Mozambique, Namibia, Nigeria, Rwanda, South Africa, Tanzania, Uganda,
Vietnam, and Zambia.
[7] Tuberculosis is the most common additional infection among people living
with HIV. It causes up to 40 percent of deaths in those with AIDS.
[8] See Moyiga Nduru, "Loud Silence on AIDS Vaccine Angers Some
Researchers," Terraviva, July 13, 2004, p. 3.
[9] Anthony Fauci, the influential and respected director of the US National
Institute of Allergy and Infectious Diseases, has called HIV a "very special
virus." He was unusually candid in a little-reported interview he gave to a
magazine distributed in Bangkok. Fauci was asked whether it was conceivable
that a vaccine to prevent HIV infection might never be developed. He
replied, "I think that's possible.... All of us are working under the
assumption that we will, but there's certainly the possibility that we're
not going to be able to develop a truly effective preventive vaccine." See
International Antiviral Therapy Evaluation Center Update, July 2004, p. 19.
[10] See Helen Epstein, "The Fidelity Fix," The New York Times Magazine,
June 13, 2004.
[11] See Preeyanat Phanayanggoor, "Social Vaccine Scheme to Give Better Sex
Education in Schools," Bangkok Post, July 13, 2004, p. 2.
[12] The report Women and HIV/AIDS: Confronting the Crisis was released in
Bangkok and jointly produced by UNAIDS, the UN Population Fund, and the UN
Development Fund for Women.
[13] See Kristin L. Dunkle and colleagues, "Gender-based Violence,
Relationship Power, and Risk of HIV Infection in Women Attending Antenatal
Clinics in South Africa," The Lancet, Vol. 363 (2004), pp. 1415–1421.
[14] See Anne-Christine d'Adesky, Moving Mountains: The Race to Treat Global
AIDS (Verso, 2004). |
|
|
