Pill Can Stop Spread of HIV in Heterosexuals

It is estimated that there are currently 33 million people in the world infected with the human immunodeficiency virus (HIV) that causes acquired immunodeficiency syndrome (AIDS). Only half of those people realize they are infected. The lion's share of HIV/AIDS cases are in Africa and Asia. Two new large studies funded by the Bill and Melinda Gates Foundation show that infection rates in heterosexual couples can be cut by up to 73% by taking a combination of two medications. Read on to find out more about these exciting new findings.

The research discussed above (involving couples in Kenya, Uganda and Botswana) found that daily AIDS drugs reduced infection rates by an average of at least 62 percent when compared with placebo (Note: The placebo end of the study was discontinued early due to the extraordinary effectiveness of the medication). These findings add to a growing body of evidence that antiretroviral drugs, used to treat AIDS patients since the mid 1990's, may also have benefit in preventing initial infection. "Effective new HIV prevention tools are urgently needed and these studies could have enormous impact in preventing heterosexual transmission," Margaret Chan, director-general of the World Health Organization (WHO), said in a statement. She said the United Nations health agency would now work with countries to use the new findings to implement better protection strategies. Back in January of 2011 the CDC, in its first official guidance on the subject, said that only high-risk gay and bisexual men should use a daily AIDS pill to protect themselves from the virus. They now plan to study the results of these new studies and issue new guidelines if deemed appropriate.

In the larger of the two studies, 4,758 heterosexual couples in Kenya and Uganda were observed. In each of the couples, one partner was HIV positive and one was not. The negative partner taking the drug tenofovir had on average 62% fewer conversions to HIV positive than those taking a placebo. In the smaller of the studies, the non-infected partner took the combination drug Truvada (tenofovir and emtricitabine). This medication cut the risk of infection by an average of 73% over the course of the study.

Lead investigator, Dr. Michael Thigpen, said Truvada proved to be safe and effective. He said the drug -- along with things like male circumcision, topical microbicide gels and condoms -- could be another tool for preventing the spread of HIV. The idea of taking a medication prospectively as a precaution to acquiring an infection is known as pre-exposure prophylaxis, or PrEP. The idea of using PrEP to fight the spread of HIV in heterosexual couples has gained traction in the past year, following results of other research showing a fall in infection rates among gay men taking AIDS drugs.

Real world availability of these traditionally costly drugs comes down to cost. Generic versions of the study medications are available as inexpensively as twenty-five cents a pill in U.S. dollars. Gilead, the leading manufacturer of HIV drugs, has agreed to share intellectual property rights on its medicines in a new patent pool. This should help to drive down the costs of the potentially life saving meds even further. Tireless efforts continue in an attempt to develop a vaccine for this terrible disease.