If the spread of HIV is to be reversed, priority must be given to reaching young people, particularly adolescent girls, and especially in sub-Saharan Africa. According to the Joint United Nations Programme on HIV/AIDS (UNAIDS), an estimated 33.4 million people worldwide were living with HIV in 2008; of these, 4.9 million were young people 15–24 years old, and 2.1 million were children under 15. Of the 2.7 million adults aged 15 and above who were newly infected with HIV in 2008, about 40 per cent were young people.

The vast majority of HIV infections still occur in sub-Saharan Africa. This region accounts for more than 80 per cent of young people 15–24 years old who are living with HIV. No matter where they live, girls and young women are especially vulnerable to HIV infection, but they are particularly so in sub-Saharan Africa. Worldwide, over 60 per cent of all young people living with HIV are young women. In sub-Saharan Africa, young women make up nearly 70 per cent of all young people living with HIV.

Data show modest progress in global prevention efforts, but they also indicate that universal access to critical prevention services and support for young people remains a distant target. The quality, targeting and efficiency of prevention efforts must be improved, and greater attention must be paid to determining exactly which subgroups of the adolescent population are most vulnerable and how to protect them.