HIV prevention in a gel?
HIV prevention in a gel?
Possibly. But as researchers scramble for new prevention methods, rectal microbicides encounter some old prejudices.
By Louis Weisberg
Copyright by The Chicago Free Press
Staff writer
For more than 20 years—ever since HIV was first identified as the causative agent of AIDS—researchers have struggled to develop a preventive vaccine. But that quest has proven elusive and hopes for an effective candidate still remain years away from reality.
Meanwhile, prevention programs in the gay community are proving increasingly ineffective, with mounting evidence that gay men are abandoning the use of condoms and safer-sexual practices. The result has been a new wave of HIV infection.
That situation, coupled with the ongoing devastation of AIDS in Africa and the developing world, has given rise to an explosion of interest in developing new prevention strategies. “The field of prevention research is becoming much more vast,” said Mitchell Warren, of the New York-based Treatment Action Group.
Researchers around the globe are studying everything from the preventive use of anti-viral medications in high-risk populations to the efficacy of circumcision in avoiding infection. While some of these approaches are hardly new or even scientific, they’re enormously promising, according to alternative prevention advocates. For example, Warren pointed to a South African study that found circumcised men were about 60 percent less likely to acquire HIV. “If we had a vaccine that looked that good, we’d all be jumping up and down,” he said.
Still, most of the new approaches under investigation are complex, controversial and less effective than a vaccine. Moreover, funding must come from private and government sources, because there’s not enough potential profit—and too many liability issues, in some cases—to attract pharmaceutical dollars. That leaves proponents of various strategies to compete against each other for scarce prevention dollars.
Of all the new efforts underway in prevention, none is likely to prove more complex and controversial than microbicides. Broadly speaking, these are existing anti-viral agents topically applied as gels, creams, sponges, suppositories or personal lubricants that can reduce the risk of infection. Unlike condoms, microbicides could be applied by women. This is critical in developing countries, where most are infected by husbands and lovers who refuse to wear condoms.
Last month, 1,300 people convened in Cape Town, South Africa, for the Microbicides 2006 Conference, the second such gathering of researchers and advocates working in the field. Reports presented at the conference suggested an effective agent could be available as early as 2010 if trials prove successful. Five potential products are currently in advanced clinical trials and the first results are expected to be announced in 2008.
But advocates are concerned about the lack of research into rectal microbicides. The physical make-up of the vagina is so different from that of the rectum that an agent that’s effective for one might prove useless for the other.
“The vagina is much tougher—it’s 40-cell layers thick as opposed to one cell,” Warren said. Anal tissue is also more absorbent and prone to abrasion and rupture, making it far more susceptible to HIV infection, he said.
Microbicide advocates say rectal microbicide research is vital, not just because anal sex is so high-risk, but due to concern that when a vaginal microbicide becomes available, people will start using it for anal sex, with unknown consequences.
Advocates believe there’s homophobia underlying the neglect of rectal microbicide research, and they stress that its importance for women is being overlooked. “At any given moment, more heterosexual women than gay men are engaging in anal intercourse,” said Anna Forbes, Global North Programs Coordinator for the Global Campaign for Microbicides.
Public health officials estimate that heterosexual anal intercourse occurs at five times the rate of homosexual intercourse—a figure based on the commonality of the practice and the vastly larger number of heterosexuals, Warren said. But heterosexual anal intercourse is vastly underreported and often officially ignored because of religious and social taboos.
None of the microbicides currently in advanced trials have been tested rectally, a situation that prompted the AIDS Foundation of Chicago to convene the International Rectal Microbicide Working Group (IRMWG) in June 2005. IRMWG presented the first-ever assessment of the state of rectal microbicide research in Cape Town.
The report stated that only $34 million has been spent to date on rectal microbicidal research and that annual expenditures are actually declining. By comparison, $140 million is invested annually on development of vaginal microbicides—and advocates said double that amount is needed.
None of the funding for microbicide research so far has come from drug companies, although some have donated their anti-viral products for testing.
IRMWG called for $350 million over the next 10-15 years to build a comprehensive rectal microbicide research program. The group also urged public health officials to “promote global, national and regional surveillance efforts to determine the percentage of HIV infection attributed to anal intercourse in order to better assess the need for rectal microbicide development.”
IRMWG co-founder Jim Pickett said his group was warmly received at the conference and he believes attitudes toward rectal microbicides are changing. Evidence of that can be seen in IRMWG’s growth. In less than a year it has mushroomed from five members to more than 200.
Later this year researchers at UCLA will begin a Phase 1 clinical trial investigating the safety and side effects of a rectal microbicide agent—the first such trial ever.
“We’re starting to feel that there’s some interest around the world in having an application that would have some basic rectal studies before it could be licensed,” Pickett said.
While microbicides would never be as effective as condoms, they would add another tool to the prevention arsenal, experts stress. Formulated as a personal lubricant, a microbicidal agent could become a potent alternative for gay men who refuse to wear condoms, Pickett said.
“This would be tapping into a behavior that already exists,” he said. “There’s research showing that 88-90 percent of gay men use lube.”
Pickett said the gay community can help spur development of rectal microbicides. “If we demand this, the market will respond,” he said. “That’s how it works. What I think is astounding is that we have been happy with just a very small handful of ways to prevent ourselves form HIV. We demand 150 kinds of coffee. How many kinds of underwear and potato chips do we buy? And yet we’ve been satisfied just with condoms.”
Possibly. But as researchers scramble for new prevention methods, rectal microbicides encounter some old prejudices.
By Louis Weisberg
Copyright by The Chicago Free Press
Staff writer
For more than 20 years—ever since HIV was first identified as the causative agent of AIDS—researchers have struggled to develop a preventive vaccine. But that quest has proven elusive and hopes for an effective candidate still remain years away from reality.
Meanwhile, prevention programs in the gay community are proving increasingly ineffective, with mounting evidence that gay men are abandoning the use of condoms and safer-sexual practices. The result has been a new wave of HIV infection.
That situation, coupled with the ongoing devastation of AIDS in Africa and the developing world, has given rise to an explosion of interest in developing new prevention strategies. “The field of prevention research is becoming much more vast,” said Mitchell Warren, of the New York-based Treatment Action Group.
Researchers around the globe are studying everything from the preventive use of anti-viral medications in high-risk populations to the efficacy of circumcision in avoiding infection. While some of these approaches are hardly new or even scientific, they’re enormously promising, according to alternative prevention advocates. For example, Warren pointed to a South African study that found circumcised men were about 60 percent less likely to acquire HIV. “If we had a vaccine that looked that good, we’d all be jumping up and down,” he said.
Still, most of the new approaches under investigation are complex, controversial and less effective than a vaccine. Moreover, funding must come from private and government sources, because there’s not enough potential profit—and too many liability issues, in some cases—to attract pharmaceutical dollars. That leaves proponents of various strategies to compete against each other for scarce prevention dollars.
Of all the new efforts underway in prevention, none is likely to prove more complex and controversial than microbicides. Broadly speaking, these are existing anti-viral agents topically applied as gels, creams, sponges, suppositories or personal lubricants that can reduce the risk of infection. Unlike condoms, microbicides could be applied by women. This is critical in developing countries, where most are infected by husbands and lovers who refuse to wear condoms.
Last month, 1,300 people convened in Cape Town, South Africa, for the Microbicides 2006 Conference, the second such gathering of researchers and advocates working in the field. Reports presented at the conference suggested an effective agent could be available as early as 2010 if trials prove successful. Five potential products are currently in advanced clinical trials and the first results are expected to be announced in 2008.
But advocates are concerned about the lack of research into rectal microbicides. The physical make-up of the vagina is so different from that of the rectum that an agent that’s effective for one might prove useless for the other.
“The vagina is much tougher—it’s 40-cell layers thick as opposed to one cell,” Warren said. Anal tissue is also more absorbent and prone to abrasion and rupture, making it far more susceptible to HIV infection, he said.
Microbicide advocates say rectal microbicide research is vital, not just because anal sex is so high-risk, but due to concern that when a vaginal microbicide becomes available, people will start using it for anal sex, with unknown consequences.
Advocates believe there’s homophobia underlying the neglect of rectal microbicide research, and they stress that its importance for women is being overlooked. “At any given moment, more heterosexual women than gay men are engaging in anal intercourse,” said Anna Forbes, Global North Programs Coordinator for the Global Campaign for Microbicides.
Public health officials estimate that heterosexual anal intercourse occurs at five times the rate of homosexual intercourse—a figure based on the commonality of the practice and the vastly larger number of heterosexuals, Warren said. But heterosexual anal intercourse is vastly underreported and often officially ignored because of religious and social taboos.
None of the microbicides currently in advanced trials have been tested rectally, a situation that prompted the AIDS Foundation of Chicago to convene the International Rectal Microbicide Working Group (IRMWG) in June 2005. IRMWG presented the first-ever assessment of the state of rectal microbicide research in Cape Town.
The report stated that only $34 million has been spent to date on rectal microbicidal research and that annual expenditures are actually declining. By comparison, $140 million is invested annually on development of vaginal microbicides—and advocates said double that amount is needed.
None of the funding for microbicide research so far has come from drug companies, although some have donated their anti-viral products for testing.
IRMWG called for $350 million over the next 10-15 years to build a comprehensive rectal microbicide research program. The group also urged public health officials to “promote global, national and regional surveillance efforts to determine the percentage of HIV infection attributed to anal intercourse in order to better assess the need for rectal microbicide development.”
IRMWG co-founder Jim Pickett said his group was warmly received at the conference and he believes attitudes toward rectal microbicides are changing. Evidence of that can be seen in IRMWG’s growth. In less than a year it has mushroomed from five members to more than 200.
Later this year researchers at UCLA will begin a Phase 1 clinical trial investigating the safety and side effects of a rectal microbicide agent—the first such trial ever.
“We’re starting to feel that there’s some interest around the world in having an application that would have some basic rectal studies before it could be licensed,” Pickett said.
While microbicides would never be as effective as condoms, they would add another tool to the prevention arsenal, experts stress. Formulated as a personal lubricant, a microbicidal agent could become a potent alternative for gay men who refuse to wear condoms, Pickett said.
“This would be tapping into a behavior that already exists,” he said. “There’s research showing that 88-90 percent of gay men use lube.”
Pickett said the gay community can help spur development of rectal microbicides. “If we demand this, the market will respond,” he said. “That’s how it works. What I think is astounding is that we have been happy with just a very small handful of ways to prevent ourselves form HIV. We demand 150 kinds of coffee. How many kinds of underwear and potato chips do we buy? And yet we’ve been satisfied just with condoms.”
posted by Carlos T Mock at 7:34 PM
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