The Branch’s goal within this program area is to promote research on the prevention of HIV/AIDS and STIs and to increase understanding of gender-specific HIV issues by:
· Increasing understanding of the transmission, acquisition, and prevention of HIV/AIDS and STIs in the female genital tract
· Developing new microbicides, especially those with contraceptive activity
· Determining optimal formulations and dosages of microbicides
· Reviewing current models and developing new ones for investigating heterosexual HIV-infection mechanisms and prevention of HIV transmission
· Evaluating hormonal and barrier contraceptive methods for their effects in preventing or enhancing heterosexual HIV and STI transmission
· Evaluating the safety and efficacy of contraceptives and infertility treatments in HIV-positive women
· Evaluating the effect of gender (i.e., exogenous and endogenous steroid hormones) on HIV/AIDS disease

The NICHD’s research program on HIV/AIDS and STIs includes activities central to the HIV prevention research endeavors of the NIH.  The HIV prevention research agenda of the NICHD focuses on preventing heterosexual and perinatal transmission of HIV/AIDS.  Microbicides, defined as products designed for intravaginal application by women prior to intercourse, could offer a female-controlled alternative for preventing transmission of HIV and other STIs.  Research on these substances is an important part of the Institute’s overall prevention agenda.

Worldwide, as well as in the United States, HIV prevalence in women is increasing, with transmission during heterosexual intercourse as the primary means, globally, by which women become infected.  HIV acquisition and progression must be considered in the context of sexual practices (i.e., vaginal cleansing), fertility regulation methods (e.g., contraceptives), and other STIs.  Additionally, some aspects of HIV disease in women differ from features observed in men.  For example, more rapid disease progression has been observed in HIV-infected women, and occurs at lower HIV viral loads than in men.  As the absolute number and percentage of HIV-positive women increases, interest in prevention of heterosexual acquisition/transmission also increases.

The effect of endogenous and exogenous steroid hormones on risk of HIV acquisition and subsequent disease progression is unknown.  In addition, incident cases of HIV occur overwhelmingly among women during their early reproductive years.  Thus, understanding the role steroid contraceptives play in HIV acquisition, progression of disease, and transmission is critical.  It is also important to determine if peri- or postmenopausal hormone therapy has any effect on HIV/AIDS.  As HIV vaccine development advances, it will also be important to examine steroid contraceptives and hormonal therapies for possible influence on the immunogenicity of potential vaccines.  More research on the possible interactions of antiretrovirals and exogenous steroid hormones will also be needed