The need for new strategies to combat the spread of HIV/AIDS has never been more urgent. Worldwide, the virus now affects more than 33 million people, more than two thirds of whom live in sub-Saharan Africa. Moreover, the proportion of women who are infected with HIV/AIDS is steadily growing. As a global crisis, HIV/AIDS shows few signs of slowing down.

According to the most recent figures from UNAIDS and the U.S. Centers for Disease Control:

• Nearly half,of the 33.2 million people living with HIV/AIDS are women. In sub-Saharan Africa, women account for 61 percent of all infected adults.
• Young women aged 15 to 24 are especially vulnerable. In sub-Saharan Africa, young women have been estimated to represent 76 percent of the total cases in that age group, outnumbering their male peers by three to one. Worldwide, 60 percent of the 15- to 24-year-olds with HIV are women.
• Approximately 2.5 million people were newly infected in 2007, with young people aged 15 to 24 accounting for about 40 percent of these new infections. More than 2 million people died of AIDS-related illnesses in 2007.

If the numbers don’t tell the whole story, consider that behind each number is a human face. Entire populations are at risk.

At the root of the epidemic is a formidable foe – a virus a million times smaller than the period at the end of this sentence yet capable of laying a destructive swath nearly the size of the globe. Although newer drugs have dramatically improved both the quality of life and life expectancy of people with HIV, they aren’t available to everyone needing them, and even for those who do have access to treatment, the drugs don’t always work or they stop working over time. At the cellular level, HIV can play a skillful game of cat and mouse, mutating with frequency in order to evade detection by drug targets. In an attempt to keep HIV from winning in its own game, treatment strategies involve a combination of several antiviral medications that take aim at the virus from multiple directions.

Similarly, prevention efforts, if they are to be successful, will require building a global fortress, with several different defense strategies working in force. Microbicides, substances designed to prevent the sexual transmission of HIV, could have a place in this comprehensive multi-pronged approach, as could vaccines; pre-exposure prophylaxis (PrEP) with oral antiretroviral therapy; antiretroviral therapy to prevent mother-to-child transmission; treatment of sexually transmitted infections; and behavior-focused strategies.