Published yesterday in Public Library of Science (PLoS), a new study done in mice with human immune systems show that mice given Pre-exposure prophylaxis (PrEP) did not contract HIV vaginally.

Though the study has not been tried in humans, it offers some hope for what may be possible to prevent women from contracting HIV vaginally--especially since the use of PrEP may be done without the consent or knowledge of a (consentual) sex partner. If this proves effective in women, the political hurdles to getting ARVs in the hands of women is going to be a huge battle.

I love the Public Library of Science for providing free access to peer-reviewed studies for people, and providing great summaries for thos of us not scientifically trained or inlcined. Here's what they said:

Editors' Summary

Background.

"Since the first cases of acquired immunodeficiency syndrome (AIDS) in 1981, the AIDS epidemic has spread rapidly. About 33 million people are now infected with the human immunodeficiency virus (HIV), the cause of AIDS. More than half of newly acquired infections now occur in women, mostly through unprotected vaginal sex with an infected male partner. Women are biologically more susceptible than men to HIV infection during vaginal intercourse and often cannot persuade their partner to use a condom. Consequently, alternative strategies that prevent intravaginal transmission of HIV (infection through the vagina) are urgently needed, particularly strategies that women can use without their partner's agreement. A vaccine would be ideal but it could be many years before an effective HIV vaccine is available so researchers are investigating other preventative strategies such as the use of microbicides—compounds that protect against HIV when applied inside the vagina—and pre-exposure treatment (prophylaxis) with antiretroviral drugs.

Why Was This Study Done?

Before any new strategy to prevent intravaginal HIV transmission is tried by women, it has to be tested in animals. Currently, this can only be done in macaques, an expensive option. In this study, the researchers have investigated whether “humanized BLT” mice could be used instead. When HIV enters the human body during vaginal intercourse, it sticks to dendritic cells (a type of immune system cell) in the vaginal lining. These cells carry the virus to the body's lymphoid tissues (collections of immune cells), where it infects and kills CD4⁺ T cells (another type of immune cell). Dendritic cells and CD4⁺ T cells have molecules on their surface that HIV recognizes. Mice are not normally susceptible to infection with HIV because their immune system cells lack these molecules. Humanized BLT mice have a nearly human immune system—BLT stands for bone marrow, liver, thymus. They are produced by implanting pieces of human fetal liver and thymus (the organ where T cells learn to recognize foreign invaders) under the kidney capsule of immunodeficient mice (animals born without an immune system) and then transplanting human hematopoietic stem cells (the source of the major immune system cells) into the mice.

What Did the Researchers Do and Find?

When the researchers examined the female reproductive tract of humanized BLT mice for human immune system cells, they found CD4⁺ T cells, dendritic cells and macrophages, all of which are involved in HIV infection. Furthermore, half of the blood cells of the BLT mice were human. Most of the BLT mice, the researchers report, were susceptible to intravaginal HIV infection as shown, for example, by a rapid loss of human CD4⁺ T cells from their blood. However, BLT mice pretreated with antiretroviral drugs (a mixture of emtricitabine and tenofovir disoproxil fumarate) were resistant to intravaginal HIV infection. As in human HIV infections, CD4⁺ T cells were also depleted in several other organs of the BLT mice after intravaginal HIV infection. Again, this depletion was prevented by antiretroviral pre-exposure prophylaxis. Finally, human CD4⁺ T cells also disappeared from the gut-associated lymphoid tissue (an important site for HIV replication and CD4⁺ T cell depletion during human HIV disease) of the BLT mice after infection with HIV.  read more »

What Do These Findings Mean?

These findings show that humanized BLT mice are susceptible to intravaginal infection with HIV and that many aspects of HIV infection in these mice closely mimic infection in people. In addition, by showing that pre-exposure prophylaxis with antiretroviral drugs prevents HIV infection, these results suggest that humanized BLT mice could be used to test new strategies designed to prevent intravaginal infection. As with all animal models, any approach that works in humanized BLT mice will still have to be tested in people. Nevertheless, these findings provide preclinical evidence that pre-exposure prophylaxis with antiretroviral drugs may be an effective way to prevent intravaginal transmission of HIV and, therefore, provide valuable support for clinical trials of this approach."

How many times will the messages of Prevention Justice be confirmed by science?

A new study published in the Journal of Adolescent Health shows that youth who are unstably housed are more likely to engage in risky sexual behavior within the first six months of being homeless. Science Daily reported that "this is the first time that researchers have followed newly homeless youth -- those who have been away from home for a period between one day and six months -- for any length of time to track how their behavior changes. The researchers examined how individual factors, such as sociodemographics, depression and substance abuse, and structural factors, such as living situations, can influence sexual behavior."

What's also interesting is what the study's author, Dr. M. Rosa Solorio, assistant professor of family medicine at the David Geffen School of Medicine at UCLA says about the study:"The reason these findings are so important is that interventions in the past have focused on addressing individual risk behavior and not on addressing structural factors, such as living situations, that might have an impact on their behavior...When we look at homeless youth, we want to consider these structural factors if we want them to reduce their risky behavior and thereby prevent sexually transmitted diseases such as HIV."

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Gay City News is reporting today that they were leaked a memo from inside the NYC Department of Health and Mental Hygiene (DOHMH) that recommended some changes to the NYC Code regulating sex venues. Whether you're in NYC or not, the document is a fascinating read of public sex policy, and may impact you if you live in another city (they talk at length about what Los Angeles and San Francisco have done).

Sara Markt, spokesperson for DOHMH said to Gay City News that "[T]his document was an internal backgrounder about our current policy, what other cities do, and what the options could be if this policy was ever to be revised," she wrote. "We don't have any plans to change the policy at this point, just wanted to evaluate how NYC and other cities are dealing with the issue... [W]e are not making any moves to change or recommend changes at this point."

But FYI, here are the options they are considering in the full memo, also published by Gay City News:

1. Continue current policy. Allow bathhouses to operate without inspection in private areas; close (or threaten to close) gay bars and other venues in which sex takes place in public.

Comment:This requires the least effort and is unlikely to cause a public outcry. It has resulted in changes in some institutions where warning letters have been sent, and may have a "chilling" effect in keeping other venues from allowing sex on the premises. However, it is likely that HIV transmission will continue to occur from unsafe sex in private areas of bathhouses and at the other venues, including "private sex parties."

Want the good news or bad news first?

I'll give you the bad news.

Sex columnist Dan Savage whose syndicated column Savage Love is read weekly by millions in alternative weeklies around the country, wrote a blog entry for the Seattle news site The Stranger about the NYT story on rising HIV infections among young MSMs. His blog post was his usual snarky self, but horribly misinformed. He writes:

" so long as gay health educators refuse to level with gay men--there's no "moderating" your meth use; you can suck too much cock; anal sex isn't a first-date activity and having anal sex with hordes of anonymous partners, even with condoms, is sure-fire way of contracting HIV--these new campaigns won't have much of an impact. And so we'll be reading this story again in a couple of years, yet another story about HIV infection that makes tragic heroes of guys like Javier Arriola and goes on to suggest that straight talk about HIV infection is part of the problem, not part of the solution."  read more »

Showing the “missing pieces” of HIV prevention puzzle in the United States, more than three hundred people poured into the downtown Atlanta streets for the PJM Unity Rally and March in Atlanta, GA, on Tuesday, December 4th, where the National HIV Prevention Conference (NHPC) ended on Wednesday. People from across different communities marched to demonstrate unity for a comprehensive HIV prevention in the US, not to be divided by community or issue.

In order to draw conference attendees from the hotel to the opening rally two blocks away at Hardy Ivy Park, a group of carolers sang an HIV prevention song to the tune of “The 12 Days of Christmas.” Other PJM folks were in the lobby, decorating marchers with the PJM sash—a white satin cloth with the red PJM Unity logo. Helping to sash people in the hotel was Miss Rhode Island 2007 Ashley Bickford, who was attending the conference as someone interested in HIV/AIDS issues.

The spirited marchers burst from the Hyatt onto Peachtree Street, blowing whistles and chanting, and made their way to Hardy Ivy Park to meet the crowd already assembled. The March MC Waheedah Shabbazz-el took the bullhorn and hyped the crowd to a frenzy, reminding the crowd, “HIV is more than a disease, It’s positive proof of injustice!” The marchers grabbed signs and flashlights from organizers and marshals, and the rally was in full swing.  read more »