4 min

Stick it up your ass

Microbicides are the up & coming safer-sex product

Credit: (Ajay Bikram Thapa)

The search for a way to kill the human immunodeficiency virus (HIV) once it’s inside the human body still has a long way to go. While much research has been dedicated to a vaccine, it remains a distant promise. However, HIV-positive people (as well as folks living with other sexually transmitted infections, or STIs) may soon have another option when it comes to safer sex.

There’s a new class of STI-preventing products in the works called microbicides; a vaginal version could be hitting the shelves in as little as three to five years. While that may be very exciting for those of us equipped with pussies, for the many ass bandits among us the question remains: what about our bums?

“Most of us in the field think the day a vaginal microbicide is licensed, is available, it will be used in the rectum,” says micro-bicide researcher Ian McGowan. “There’ll be no safety perhaps to support that, but people are people; that’s what they’ll do.”

Not only is it possible that anal use of vaginal microbicides won’t be safe, it might not even help to prevent anal transmission of STIs.

“We may need a completely different formulation for the rectum,” says McGowan.

Currently there are five vaginal microbicides in final phase trials in sub-Saharan Africa, where HIV-infection rates are among the highest in the world. Some of the microbicides in the works will protect against a plethora of STIs, including incurables such as HIV, human papilloma virus (HPV) and herpes. Others act on only one STI. Some even manage to kill STIs without killing the sperm, which means that HIV-positive men could someday father children without infecting either the mother or child.

Microbicides could eventually come in the form of a gel, cream, suppository, film, lube or even a sponge or vaginal ring. Microbicides use a variety of methods to keep us safe, including killing or immobilizing bugs, blocking them by creating a physical barrier or preventing infection from taking hold once it has entered the body.

So how long will we have to wait until anal microbicides are widely available? At this stage in the research, it’s difficult to say. The microbicides undergoing trials show promise, but like many research fields, it is underfunded and understaffed.

“There’s currently about $7 million a year being invested in rectal microbicide research,” says Marc-Andre LeBlanc, microbicide advocate and member of the steering committee for the International Rectal Microbicides Working Group (IRMWG). “If you want to have a product within the next 10 years available on the market, we need to increase that investment fivefold to $35 million a year, and we’ll need obviously a lot more researchers involved in researching rectal microbicides.”

McGowan concurs. He predicts that it will be at least a decade before you’ll be seeing rectal microbicides at a pharmacy near you. “I think at the moment the science isn’t ready for primetime in the rectum.”

It’s not just a case of hetero-sexist policymakers and researchers assuming that ass play is just for fags, either; anal applications present some challenging technical issues.

For example, because the rectum leads into the gastro-intestinal (GI) tract, researchers need to figure out how far potentially infected sperm can travel up the GI tract, and find a delivery method for the microbicide that will keep us protected from even the furthest-flung sperm.

Safety is also an issue. For example, the regular use of Nonoxynyl-9, an STI-killing detergent sometimes found in lubes or on lubricated condoms, has been shown to cause damage to the cell walls of the vagina and, even more so, the rectum, which can make us even more vulnerable to STIs (including HIV) than we would be otherwise.

“The vagina has literally 15 to 30 layers of cells. In the rectum, there’s one layer of cells,” explains McGowan, “so it’s not really surprising that when you put the same product into both… you may see more damage in the rectum than in the vagina.”

McGowan’s group at the University Of California Los Angeles is now in the process of researching how safe microbicides designed for vaginal use would be if used anally; they recently started human safety trials for rectal use of a microbicide called UC-781.

UC-781 is a reverse transcriptase inhibitor; it binds rapidly to HIV molecules, rendering them ineffective, and disassociates very slowly. What’s more, it seems to be effective even in a one-to-one ratio with HIV molecules, which means that it won’t take much of it to be effective. Currently, UC-781 is in the first phase of human trials for vaginal safety. Before it can go on the market, it will need to pass three more phases of testing — a process that could take another five to seven years to complete.

Currently, only a handful of researchers worldwide are working on rectal microbicides. In the hopes of increasing interest and funding, those researchers have banded together with advocates and community activists to form the IRMWG.

“It’s sort of a two-pronged approach,” says LeBlanc. “You want to certainly encourage more funding to the field, and at the same time you have to encourage researchers to become involved in that area of research as well.”

If the IRMWG has its way then Canada, Australia, Germany and other western European countries will be at the forefront of these efforts. Although the US National Institute Of Health is already studying rectal microbicides, many fear that the US government might pull funding for all microbicide research if funding toward exclusively anal studies were widely publicized.

“You really need to be strategic about advocating for more funding, and which doors you knock on,” says LeBlanc.

Canada has already contributed two vaginal microbicides: cellulose sulfate and the Invisible Condom. Cellulose sulfate was originally developed by Toronto-based Polydex Pharmaceuticals to protect against HIV; it is currently undergoing phase three trials funded by a group in the US.

Although the Invisible Condom is currently only in phase one and two human trials, it shows a great deal of promise. Developed in Laval, Quebec by researcher Michel Bergeron, it may help protect against HIV, herpes, HPV, chlamydia, gonorrhea and pregnancy. This unusual product is liquid at room temperature, but becomes a gel at body temperature. Researchers expect it to act as both a physical and chemical barrier to infection-carrying sperm.

While microbicides like the Invisible Condom may protect against virtually every monster under the bed, researchers continue to emphasize the use of condoms. Although microbicides can protect against known bugs, only a latex or polyurethane condom will protect against new STIs as they evolve. Instead, microbicides are meant for use by people unable to convince their partners to use condoms (such as in abusive situations), or as a backup method (for example, in case a condom breaks).