By Chief K. Masimba Biriwasha | OpEd
Microbicide research has gained momentum in recent years with focus largely on products to prevent HIV during vaginal sex. However, there is a growing momentum to develop rectal microbicides for women, men, and transgender individuals around the world who engage in anal intercourse.
Microbicides are products designed to prevent or reduce the sexual transmission of HIV or other sexually transmitted infections when applied inside the vagina or rectum. Most vaginal microbicides are being tested as gels or rings, while rectal microbicides are primarily being tested as gels.
Rectal microbicides are products – that could take the form of gels or lubricants – being developed and tested to reduce a person’s risk of HIV or other sexually transmitted infections from anal sex. In spite of the public health need for rectal microbicide research, there is serious institutional, socio-cultural and political stigma around the issue.
According to estimates, the risk of becoming infected with HIV through anal sex is 10 to 20 times greater than vaginal sex because the rectal lining, the mucosa, is thinner and much more fragile than the lining of the vagina. Because the rectal lining is only one-cell thick, the virus can more easily reach immune cells to infect.
Although the rate of new infections is stabilizing in many countries around the world, HIV continues to disproportionately affect racial minorities and men who have sex with men. It is estimated that five to ten percent of the world’s population engages in anal sex.
Globally, men who have sex with men are 19 times more likely to be infected with HIV than the general population. Unprotected anal sex is the primary driver of the HIV epidemic among this population.
For decades, the primary approach to HIV prevention for anal sex has been consistent and correct use of male condoms. Male condoms are an extremely effective method to prevent HIV, but many people are unable or reluctant to use them.
Rectal microbicides are products – that could take the form of gels or lubricants – being developed and tested to reduce a person’s risk of HIV or other sexually transmitted infections from anal sex.
If proven effective, rectal microbicides could protect against HIV in people who are unable or reluctant to use condoms. Unlike condoms, they could provide an alternative way to reduce risk that is not controlled by one’s sexual partner and possibly enhance sexual pleasure, helping to motivate consistent use.
Rectal microbicides could offer both primary protection in the absence of condoms and back-up protection if a condom breaks or slips off during anal intercourse. Such an alternative is essential if we are to address the full spectrum of prevalent sexual practices and the basic human need for accessible, user-controlled HIV and STD prevention tools
Rectal microbicides research is in the early phase of clinical development due in part to scientific challenges related to the biology of the rectum, and cultural reluctance to address anal sex.
Most critically testing the safety and acceptability of microbicides designed specifically for rectal use is key to ensuring their effectiveness in preventing HIV infection among people who engage in anal sex.
Researchers need to first be sure rectal microbicides are safe and then conduct additional studies to find out whether they are effective against HIV.