Health Policy, Volume 84, Issues 2-3, December 2007, Pages 133-141
Binod Nepal ,(nepalbinod@....
National Centre for Social and Economic Modelling, University of
Canberra, ACT 2601, Australia
Abstract
AIDS denial has long been viewed as the obstacle to forging effective
response in many Asian countries. This article examines the
dimensions and roots of this phenomenon. It identifies seven types of
views, attitudes, or tendencies that can be described as denial,
dissent, disagreements, or doubts.
Three major factors underlying the AIDS denial are discussed. These are (1)
historical impressions that STDs are Western diseases, (2) desire of some Asian
leaders to forge Eastern points of view, and (3) long-held negative image
towards the peoples or groups who happened to be at the front-line of the
population groups exposed to the epidemic. The third factor is the most
important source of denial.
AIDS denial is not a new and isolated phenomenon but the one shaped by the
global and historical institutions. Asian AIDS denial reflects the authoritarian
and moralist grievances arising from the perceived deterioration of traditional
moral order.
Fax: +61 2 6201 2751.
Health Policy. Volume 84, Issues 2-3, December 2007, Pages 133-141
doi:10.1016/j.healthpol.2007.04.011
Copyright © 2007 Elsevier Ireland Ltd All rights reserved.
Sunday 25 November 2007
Thursday 22 November 2007
UN slashes AIDS estimates to 33 million
http://au.news.yahoo.com/071120/2/150ly.html#
Tuesday November 20, 03:12 PM
The United Nations has slashed its estimates of how many people are infected with the AIDS virus, from nearly 40 million to 33 million.
In a report, the UN says revised estimates on HIV in India account for a large part of the decrease.
The agency admitted it overestimated how many people were infected with the incurable virus, and said better methods of collecting data showed it was not quite a common as feared.
"The single biggest reason for this reduction was the intensive exercise to assess India's HIV epidemic, which resulted in a major revision of that country's estimates," the report said.
After originally estimating some 5.7 million people were infected in India, the UN more than halved that estimate, to 2.5 million.
But the numbers nonetheless show the epidemic is overwhelming and that efforts to fight HIV must still be stepped up, said officials at the UN AIDS agency UNAIDS.
"These improved data present us with a clearer picture of the AIDS epidemic, one that reveals both challenges and opportunities," UNAIDS Executive Director Dr Peter Piot said in a statement.
"Unquestionably, we are beginning to see a return on investment - new HIV infections and mortality are declining and the prevalence of HIV levelling. But with more than 6,800 new infections and over 5,700 deaths each day due to AIDS, we must expand our efforts in order to significantly reduce the impact of AIDS worldwide."
The new numbers suggest that some 33.2 million people are infected with the human immunodeficiency virus - about 30.8 million adults and 2.5 million children.
UNAIDS estimated that 1.7 million people became newly infected in sub-Saharan Africa this year, a significant reduction since 2001.
But Africa remains by far the continent hardest hit by AIDS, with 22.5 million people infected with HIV.
"Eight countries in this region now account for almost one-third of all new HIV infections and AIDS deaths globally," said UNAIDS.
"In Asia, the estimated number of people living with HIV in Vietnam has more than doubled between 2000 and 2005 and Indonesia has the fastest growing epidemic."
The report gives two reasons for the downward revisions - one is better data and the other is an actual decrease in the number of new infections.
"UNAIDS and (the World Health Organisation) are now working with better information from many more countries," UNAIDS said.
The number of new HIV infections each year likely peaked in the late 1990s at 3 million and was estimated at 2.5 million for 2007, UNAIDS said.
"This reflects natural trends in the epidemic, as well as the result of HIV prevention efforts. Of the total difference in the estimates published in 2006 and 2007, 70 per cent are due to changes in six countries: Angola, India, Kenya, Mozambique, Nigeria, and Zimbabwe," the report said.
"In both Kenya and Zimbabwe, there is increasing evidence that a proportion of the declines is due to a reduction of the number of new infections which is, in part due to a reduction in risky behaviours."
The UN also changed its estimate on how long it takes to die of AIDS if not treated from 9 years to 11 years.
Tuesday November 20, 03:12 PM
The United Nations has slashed its estimates of how many people are infected with the AIDS virus, from nearly 40 million to 33 million.
In a report, the UN says revised estimates on HIV in India account for a large part of the decrease.
The agency admitted it overestimated how many people were infected with the incurable virus, and said better methods of collecting data showed it was not quite a common as feared.
"The single biggest reason for this reduction was the intensive exercise to assess India's HIV epidemic, which resulted in a major revision of that country's estimates," the report said.
After originally estimating some 5.7 million people were infected in India, the UN more than halved that estimate, to 2.5 million.
But the numbers nonetheless show the epidemic is overwhelming and that efforts to fight HIV must still be stepped up, said officials at the UN AIDS agency UNAIDS.
"These improved data present us with a clearer picture of the AIDS epidemic, one that reveals both challenges and opportunities," UNAIDS Executive Director Dr Peter Piot said in a statement.
"Unquestionably, we are beginning to see a return on investment - new HIV infections and mortality are declining and the prevalence of HIV levelling. But with more than 6,800 new infections and over 5,700 deaths each day due to AIDS, we must expand our efforts in order to significantly reduce the impact of AIDS worldwide."
The new numbers suggest that some 33.2 million people are infected with the human immunodeficiency virus - about 30.8 million adults and 2.5 million children.
UNAIDS estimated that 1.7 million people became newly infected in sub-Saharan Africa this year, a significant reduction since 2001.
But Africa remains by far the continent hardest hit by AIDS, with 22.5 million people infected with HIV.
"Eight countries in this region now account for almost one-third of all new HIV infections and AIDS deaths globally," said UNAIDS.
"In Asia, the estimated number of people living with HIV in Vietnam has more than doubled between 2000 and 2005 and Indonesia has the fastest growing epidemic."
The report gives two reasons for the downward revisions - one is better data and the other is an actual decrease in the number of new infections.
"UNAIDS and (the World Health Organisation) are now working with better information from many more countries," UNAIDS said.
The number of new HIV infections each year likely peaked in the late 1990s at 3 million and was estimated at 2.5 million for 2007, UNAIDS said.
"This reflects natural trends in the epidemic, as well as the result of HIV prevention efforts. Of the total difference in the estimates published in 2006 and 2007, 70 per cent are due to changes in six countries: Angola, India, Kenya, Mozambique, Nigeria, and Zimbabwe," the report said.
"In both Kenya and Zimbabwe, there is increasing evidence that a proportion of the declines is due to a reduction of the number of new infections which is, in part due to a reduction in risky behaviours."
The UN also changed its estimate on how long it takes to die of AIDS if not treated from 9 years to 11 years.
Tuesday 13 November 2007
Joint Statement of the Three Delegations in support of Civil Society's uniquerole in responding to HIV/TB/Malaria in ChinaKunming, China, 16 th Global
November 12, 2007
Having had some extremely valuable formal and informal interactions with a range of China Civil Society and Communities representatives over the last 5 days, the Communities Delegation along with Developed and Developing Country NGOs Delegation would like to strongly recommend to the Global Fund Board that a special attention is given to the need for strengthening Civil Society involvement and participation in the implementation of GF programs in China.
As with all grants there will be challenges in implementation. In particular, in the case of China and the recently-approved round 6, community and grassroots organizations cannot register to be legally recognized as civil society organizations.
We expect that these grassroots organizations, registered or not, should have access to the funds so that the implementation efforts will reflect the desired goal of the proposed program.
We, the members of the three civil society delegations to the Fund feel responsible and accountable to ensure that our counterparts in China are alsoable to access and utilize the opportunities of being a stakeholder in the Global Fund.
We are committed to ensure that the voices and aspirations of all communities living with the diseases in China are heard and that their basic rights, particularly the right to information and services are properly secured.
We expect the Global Fund to take the lead in ensuring its commitment to strengthen capacity building and mobilization of Civil Society across the world, including China, so that our collective goal of containing and reversing the spread of HIV/TB/Malaria is achieved.
We, the three civil society delegations, will continue to proactively engage with Chinese civil society to ensure their key role in the response tothe three diseases is recognized and we will work in close collaboration withall of you until this is achieved.
Communities Delegation
Developed Countries NGO Delegation
Developing Countries NGO Delegation to the Global Fund Board
Published at AIDS-ASIA yahoogroups, Tuesday, November 13,2007
Having had some extremely valuable formal and informal interactions with a range of China Civil Society and Communities representatives over the last 5 days, the Communities Delegation along with Developed and Developing Country NGOs Delegation would like to strongly recommend to the Global Fund Board that a special attention is given to the need for strengthening Civil Society involvement and participation in the implementation of GF programs in China.
As with all grants there will be challenges in implementation. In particular, in the case of China and the recently-approved round 6, community and grassroots organizations cannot register to be legally recognized as civil society organizations.
We expect that these grassroots organizations, registered or not, should have access to the funds so that the implementation efforts will reflect the desired goal of the proposed program.
We, the members of the three civil society delegations to the Fund feel responsible and accountable to ensure that our counterparts in China are alsoable to access and utilize the opportunities of being a stakeholder in the Global Fund.
We are committed to ensure that the voices and aspirations of all communities living with the diseases in China are heard and that their basic rights, particularly the right to information and services are properly secured.
We expect the Global Fund to take the lead in ensuring its commitment to strengthen capacity building and mobilization of Civil Society across the world, including China, so that our collective goal of containing and reversing the spread of HIV/TB/Malaria is achieved.
We, the three civil society delegations, will continue to proactively engage with Chinese civil society to ensure their key role in the response tothe three diseases is recognized and we will work in close collaboration withall of you until this is achieved.
Communities Delegation
Developed Countries NGO Delegation
Developing Countries NGO Delegation to the Global Fund Board
Published at AIDS-ASIA yahoogroups, Tuesday, November 13,2007
Interpol to fight sale of fake medicines in Africa
http://health.yahoo.com/news/afp/policeinterpolafricacounterfeitme
dicinehealth-print.html
By AFP
International police body Interpol will join the fight against the
growing trade in Africa in fake drugs for tuberculosis, malaria and
HIV/AIDS which threatens the lives of thousands, a senior official
said Tuesday.(AFP/File/Issouf Sanogo)
MARRAKECH, Morocco (AFP) - International police body Interpol
will join the fight against the growing trade in Africa in fake drugs for
tuberculosis, malaria and HIV/AIDS which threatens the lives of
thousands, a senior official said Tuesday.
The agency's efforts will begin later this year and will build on its
success in tackling the problem in Latin America and Southeast Asia,
said John Newton, the manager of Interpol's intellectual property
rights project.
"We have learned a lot of lessons in those regions and we are now
able to apply those to Africa," he told AFP on the sidelines of
Interpol's annual general assembly in Marrakech in southern Morocco.
Congo, Nigeria, Senegal and Sudan asked the 186-member police
body at the gathering for for help in stopping smuggling networks
from making fake drugs readily available in their markets and
sometimes even pharmacies, he said.
"The Africans are very keen for Interpol to work with them on this
subject," said Newton.
Interpol will train police in Africa on how to smash counterfeit
medicine smuggling networks, coordinate police operations and track
the flow of fake drugs from southeast Asia and other parts of the
world to the continent.
As it has in other regions, the global police body will work with the
World Health Organization and drug companies to tackle the problem.
"We can bridge the gap between law enforcement and the public
health sector, we are able to bring the two areas together," said Newton.
The World Health Organization estimates that up to 30 percent of the
medicine sold in Africa is fake.
Counterfeit medicine networks take advantage of Africa's poor or
non-existent drug regulatory systems to dump drugs with little or no
active ingredient in the continent, experts say.
Interpol carried out its first-ever operation solely dedicated to the
trade in fake medicine in 2005 in seven southeast Asian countries.
"We are concerned about counterfeit medicines for life-threatening
diseases such as malaria, tuberculosis and HIV/AIDS and increasingly
getting involved in this area," said Newton.
The US-based Center for Medicines in the Public Interest estimates
that global counterfeit drug sales will rise to 75 billion dollars by
2010, a 90 percent increase over 2005.
dicinehealth-print.html
By AFP
International police body Interpol will join the fight against the
growing trade in Africa in fake drugs for tuberculosis, malaria and
HIV/AIDS which threatens the lives of thousands, a senior official
said Tuesday.(AFP/File/Issouf Sanogo)
MARRAKECH, Morocco (AFP) - International police body Interpol
will join the fight against the growing trade in Africa in fake drugs for
tuberculosis, malaria and HIV/AIDS which threatens the lives of
thousands, a senior official said Tuesday.
The agency's efforts will begin later this year and will build on its
success in tackling the problem in Latin America and Southeast Asia,
said John Newton, the manager of Interpol's intellectual property
rights project.
"We have learned a lot of lessons in those regions and we are now
able to apply those to Africa," he told AFP on the sidelines of
Interpol's annual general assembly in Marrakech in southern Morocco.
Congo, Nigeria, Senegal and Sudan asked the 186-member police
body at the gathering for for help in stopping smuggling networks
from making fake drugs readily available in their markets and
sometimes even pharmacies, he said.
"The Africans are very keen for Interpol to work with them on this
subject," said Newton.
Interpol will train police in Africa on how to smash counterfeit
medicine smuggling networks, coordinate police operations and track
the flow of fake drugs from southeast Asia and other parts of the
world to the continent.
As it has in other regions, the global police body will work with the
World Health Organization and drug companies to tackle the problem.
"We can bridge the gap between law enforcement and the public
health sector, we are able to bring the two areas together," said Newton.
The World Health Organization estimates that up to 30 percent of the
medicine sold in Africa is fake.
Counterfeit medicine networks take advantage of Africa's poor or
non-existent drug regulatory systems to dump drugs with little or no
active ingredient in the continent, experts say.
Interpol carried out its first-ever operation solely dedicated to the
trade in fake medicine in 2005 in seven southeast Asian countries.
"We are concerned about counterfeit medicines for life-threatening
diseases such as malaria, tuberculosis and HIV/AIDS and increasingly
getting involved in this area," said Newton.
The US-based Center for Medicines in the Public Interest estimates
that global counterfeit drug sales will rise to 75 billion dollars by
2010, a 90 percent increase over 2005.
Saturday 10 November 2007
Russian scientists offer hope for HIV vaccine
http://en.rian.ru/russia/20071005/82647847.html
NOVOSIBIRSK October 5 (RIA Novosti) - Scientists at the Russian virology and biotechnology Vector research centre in Novosibirsk, West Siberia have developed a potential HIV vaccine.
"As we know there is no HIV vaccine. The Americans had high hopes of developing one, but the three vaccines developed most recently all failed trials. Today the specialists from Vector said there is a hope for an effective vaccine," a leading geneticist, Vladimir Shumny, said on Friday.
The scientist added that it is difficult to develop an HIV vaccine as the virus is constantly mutating. He also said that the polymorphous vaccine created by the research center might help to effectively prevent HIV, however.
At the same time, Shumny claimed that lengthy legal procedures could complicate the vaccine's chances of passing the necessary medical trials, not to mention getting it registered with the appropriate authorities.
"The first phase of trials will take at least three years," he explained.
A researcher at Vektor added that it was still too early to speak about the effectiveness of the vaccine, as the first phase of the trials has not started and its safety has not yet been proven.
A total of 37 HIV vaccines have been developed, but none of them have been successful, she added.
The Russian government has allocated one billion rubles ($39.4 million) to develop a HIV vaccine.
Since 1987, when the first HIV case was first reported in Russia, 388,871 cases have been registered in the country, and HIV-infected women have given birth to 1,200 children. Among the most infected areas in Russia are Moscow, Irkutsk, Samara, Orenburg, and the Leningrad Region.
At the end of 2005, 40.3 million people were HIV-infected worldwide, including 17.5 million women and 2.3 million children under the age of 15.
Pre-treatment CD4 Count Predicts CD4 Gains on Treatment
http://www.aidsmeds.com/articles/hiv_cd4_uk_1667_13356.shtml
October 30, 2007
By David EvansThe higher a person’s CD4 count upon starting HIV treatment, the higher their CD4 count will be 60 months later, say British researchers at the 11th European AIDS Conference in Madrid.
Rachael Hughes, MSc, of the department of social medicine at the University of Bristol in England, and her colleagues analyzed data involving 4,559 patients participating in the U.K. collaborative HIV Cohort (UK-CHIC), all of whom had maintained undetectable viral loads for at least six months after starting HIV treatment. Data were available for 631 patients who had been followed for greater than 60 months.
The research team found that CD4 gains were universally good among all of the patients in the study, regardless of their starting CD4 count. Those who started treatment with the lowest CD4 count, between 0 and 100, had the largest gains of up to 379 cells, while those who started with the highest, 500 and above, had the least gains, roughly 100 cells.
However, the average CD4 count 60 months after starting treatment was 100 cells lower among those who started treatment with CD4 counts between 350 and 499, compared with those who started with between 500 and 749 cells.
While these data suggest that people who start HIV treatment earlier will, on average, do better immunologically than those who start later, they also illustrate that almost all patients, regardless of their starting CD4 counts, can expect robust CD4 increases as a result of treatment. This research also concludes that CD4 gains are most noticeable during the first few months of treatment but do continue even after a year of treatment.
Source:
Hughes R, Sabin C, Sterne J. Long-term Trends in CD4 Count in Patients Starting HAART: UK-CHIC Study [Abstract P18.4/04] 11th European AIDS Conference, Madrid, 2007.Early Treatment Reduces Risk of Three Common Complications
http://www.aidsmeds.com/articles/kidney_neuropathy_anemia_1667_13376.shtml
November 2, 2007
Does starting HIV treatment early increase the risk of complications like peripheral neuropathy, anemia and kidney problems? On the contrary, say new data from the HIV Outpatient Study (HOPS) to be reported in an upcoming issue of the Journal of Acquired Immune Deficiency Syndromes (JAIDS).Peripheral neuropathy, anemia and kidney problems are common occurrences in people with HIV, notably those on antiretroviral (ARV) treatment. In turn, some experts have suggested that starting treatment earlier than is currently recommended—a CD4 count below 350 cells—may result in an upswing in these complications among otherwise healthy people living with the virus.
The HOPS investigators, under the direction of Kenneth Lichtenstein, MD, of the University of Colorado in Denver followed 2,165 HIV-positive patients who started ARV treatment with varying CD4 counts for approximately three years. Patients were divided into three groups: those who started with CD4s below 200, between 200 and 349, and 350 or higher.
Among patients starting therapy with CD4s above 200, the number of new cases (incidence) of peripheral neuropathy, anemia and kidney problems—and the risk for these complications—was lower, compared with those starting HIV treatment with CD4s below 200. The incidence and risks of kidney problems were similar among those starting therapy with CD4s above 350 versus 200 to 349, but the risk of peripheral neuropathy and anemia was found to be lower among those starting with 350 or more CD4s.
Dr. Lichtenstein’s group also reported that the incidence of each condition decreased rapidly and remained low the longer patients remained on ARV therapy. The risk of these complications occurring was actually highest during the first three months of treatment, regardless of the pre-therapy CD4 count.
Assessing a Failed AIDS Vaccine
After 20 years of defeat, it appeared that science may have finally developed a viable vaccine against AIDS. Merck's new drug, V520, was being tested in a huge clinical trial, involving 3,000 people in 15 cities, and it was widely considered the most promising new candidate in the field.
But last September, when Merck analyzed its initial trial data, it found that the vaccine had failed - and failed miserably. On Wednesday, the company issued its first report on the V520 trials, revealing that the drug did not protect against HIV, and more disturbingly, actually increased some people's susceptibility to the virus. "I don't think anyone imagined the results would be so definitively negative so quickly," says Dr. Gary Nabel, director of the Vaccine Research Center at the National Institutes of Health.
V520 may have failed, but somewhere in the details of the drug's nonsuccess, scientists hope to find insight into what will make future vaccines work. After all, V520 is just one of about 50 experimental HIV vaccines that are currently being tested in clinical trials, and almost all of them are designed to function the same way. While most vaccines expose the body to weakened or killed viruses, or pieces of them, to boost production of antibodies - proteins that recognize invading cells and flag them for destruction - that tack alone was too feeble to fend off HIV.
The new class of vaccines, including V520, takes a more direct route: They trigger cell-mediated immunity, which marshals killer T cells that both recognize and destroy viruses and bacteria, and can lead to a more robust, specific and longer-lived immune defense. It's not yet clear why V520 didn't work, but one theory involves its vector, or delivery vehicle. Like almost every other AIDS vaccine in development, Merck's drug used the common cold virus to transport its payload - three synthetic HIV genes - into the body's cells. What makes the adenovirus ideal for the task is precisely the reason colds make us so miserable - once inside a host, the cold virus infects cells and starts to replicate quickly.
The down side to that efficiency, however, is that cold viruses are so common that most people have developed a certain level of tolerance to them; if the adenovirus fails to excite the immune system, then any bugs piggybacked on the virus, such as HIV genes, will also slip past immune defenses. That's exactly what appears to have happened in the Merck trial: People with the highest pre-existing immunity to the common cold also had the highest rates of infection with HIV.
"It could be due to chance, or to differences in the populations we studied, or to something related to the vaccine itself," says Dr. Keith Gottesdiener, vice president of Vaccine and Infectious Disease Clinical Research at Merck. "The 'why' is still not well known.
" Researchers have already set about trying to figure it out. "We have to remember that Merck's was a single product testing a vaccine concept, which is that T cell immunity can protect against HIV infection," says Nabel. "And we know there are other ways to stimulate T cell immunity." Nabel is ready to test one such method, a vaccine similar to Merck's that uses different HIV genes and a "prime-boost" approach that involves two injections spaced a few months apart, instead of one shot, to maximize the stimulation of the body's T cells.
Other researchers, like Dr. David Ho, director of the Aaron Diamond AIDS Research Center in New York City and the recipient of a $25 million grant from the Gates Foundation to study novel vaccine strategies, think that the cold virus isn't the best way to deliver HIV. Ho is exploring the possibility that a different vector, such as the chicken pox virus, or perhaps no vector at all - simply injecting snippets of naked HIV DNA - could yield stronger immune responses.
At the International AIDS Vaccine Initiative (IAVI), a non-profit group of public and private partners focused on funding and accelerating AIDS vaccine research, scientists are studying the use of crippled, live strains of HIV - based on the success of other such live attenuated vaccines against polio and measles - which they think might be critical to waking up the right immune system defenses. "There is something magical about the replicating virus, because it has virtually its entire genome," says Dr. Seth Berkley, president of IAVI. His group is also investigating ways to stimulate so-called neutralizing antibodies, a special class of antibodies that appear to be able to defuse HIV.
Despite the ongoing study, experts argue that none of it will succeed without some basic changes in the way it's conducted. Most research occurs in isolation; there's little coordination among labs and no network through which data can be shared, making it difficult for scientists to learn from each other's missteps. Worse, it takes years to get regulatory approval to start a human trial for a new vaccine - not to mention enrolling the volunteers and training the right personnel - so, by the time experiments get underway, the science around which the vaccine was built has long since become outdated. "The trials are not informing science at the moment," says Dr. Alan Bernstein, executive director of the Global HIV Vaccine Enterprise, an alliance of independent organizations dedicated to accelerating HIV vaccine research. "Science - and vaccine development - is an iterative process, except that in HIV vaccine research, there isn't a lot of iteration going on."
The Enterprise, which was founded in 2005, intends to change that. With funding from the Gates Foundation, Wellcome Trust, National Institutes of Health and the European Union, it will serve as a hub for guiding worldwide HIV vaccine research. We want to ensure that the trials are done faster, better and smarter, says Bernstein. And hopefully, with more success. [TM]
But last September, when Merck analyzed its initial trial data, it found that the vaccine had failed - and failed miserably. On Wednesday, the company issued its first report on the V520 trials, revealing that the drug did not protect against HIV, and more disturbingly, actually increased some people's susceptibility to the virus. "I don't think anyone imagined the results would be so definitively negative so quickly," says Dr. Gary Nabel, director of the Vaccine Research Center at the National Institutes of Health.
V520 may have failed, but somewhere in the details of the drug's nonsuccess, scientists hope to find insight into what will make future vaccines work. After all, V520 is just one of about 50 experimental HIV vaccines that are currently being tested in clinical trials, and almost all of them are designed to function the same way. While most vaccines expose the body to weakened or killed viruses, or pieces of them, to boost production of antibodies - proteins that recognize invading cells and flag them for destruction - that tack alone was too feeble to fend off HIV.
The new class of vaccines, including V520, takes a more direct route: They trigger cell-mediated immunity, which marshals killer T cells that both recognize and destroy viruses and bacteria, and can lead to a more robust, specific and longer-lived immune defense. It's not yet clear why V520 didn't work, but one theory involves its vector, or delivery vehicle. Like almost every other AIDS vaccine in development, Merck's drug used the common cold virus to transport its payload - three synthetic HIV genes - into the body's cells. What makes the adenovirus ideal for the task is precisely the reason colds make us so miserable - once inside a host, the cold virus infects cells and starts to replicate quickly.
The down side to that efficiency, however, is that cold viruses are so common that most people have developed a certain level of tolerance to them; if the adenovirus fails to excite the immune system, then any bugs piggybacked on the virus, such as HIV genes, will also slip past immune defenses. That's exactly what appears to have happened in the Merck trial: People with the highest pre-existing immunity to the common cold also had the highest rates of infection with HIV.
"It could be due to chance, or to differences in the populations we studied, or to something related to the vaccine itself," says Dr. Keith Gottesdiener, vice president of Vaccine and Infectious Disease Clinical Research at Merck. "The 'why' is still not well known.
" Researchers have already set about trying to figure it out. "We have to remember that Merck's was a single product testing a vaccine concept, which is that T cell immunity can protect against HIV infection," says Nabel. "And we know there are other ways to stimulate T cell immunity." Nabel is ready to test one such method, a vaccine similar to Merck's that uses different HIV genes and a "prime-boost" approach that involves two injections spaced a few months apart, instead of one shot, to maximize the stimulation of the body's T cells.
Other researchers, like Dr. David Ho, director of the Aaron Diamond AIDS Research Center in New York City and the recipient of a $25 million grant from the Gates Foundation to study novel vaccine strategies, think that the cold virus isn't the best way to deliver HIV. Ho is exploring the possibility that a different vector, such as the chicken pox virus, or perhaps no vector at all - simply injecting snippets of naked HIV DNA - could yield stronger immune responses.
At the International AIDS Vaccine Initiative (IAVI), a non-profit group of public and private partners focused on funding and accelerating AIDS vaccine research, scientists are studying the use of crippled, live strains of HIV - based on the success of other such live attenuated vaccines against polio and measles - which they think might be critical to waking up the right immune system defenses. "There is something magical about the replicating virus, because it has virtually its entire genome," says Dr. Seth Berkley, president of IAVI. His group is also investigating ways to stimulate so-called neutralizing antibodies, a special class of antibodies that appear to be able to defuse HIV.
Despite the ongoing study, experts argue that none of it will succeed without some basic changes in the way it's conducted. Most research occurs in isolation; there's little coordination among labs and no network through which data can be shared, making it difficult for scientists to learn from each other's missteps. Worse, it takes years to get regulatory approval to start a human trial for a new vaccine - not to mention enrolling the volunteers and training the right personnel - so, by the time experiments get underway, the science around which the vaccine was built has long since become outdated. "The trials are not informing science at the moment," says Dr. Alan Bernstein, executive director of the Global HIV Vaccine Enterprise, an alliance of independent organizations dedicated to accelerating HIV vaccine research. "Science - and vaccine development - is an iterative process, except that in HIV vaccine research, there isn't a lot of iteration going on."
The Enterprise, which was founded in 2005, intends to change that. With funding from the Gates Foundation, Wellcome Trust, National Institutes of Health and the European Union, it will serve as a hub for guiding worldwide HIV vaccine research. We want to ensure that the trials are done faster, better and smarter, says Bernstein. And hopefully, with more success. [TM]
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