​California (CA) has the largest number of new human immunodeficiency virus (HIV) diagnoses in the United States, led by Los Angeles, San Francisco, and San Diego counties. The California Integrated HIV Surveillance, Prevention and Care Plan has detailed multiple strategies and objectives to get to zero new HIV infections, zero AIDS-related deaths, and zero stigma and discrimination against people living with HIV (PLWH).

A key strategy for “Getting to Zero” in California is increasing utilization of pre-exposure prophylaxis (PrEP). PrEP refers to the use of antiretroviral medications to prevent HIV infection prior to exposure. Taken as a single daily oral tablet, studies show that PrEP reduces the risk of contracting HIV from sexual intercourse by more than 90% and reduces the risk from injection drug use by more than 70 percent. However, despite its efficacy, data from Gilead Pharmaceuticals, the maker of the currently approved PrEP regimen, indicate that rates of PrEP uptake vary by demographic characteristics, risk group, and region in the US. In addition, racial/ethnic disparities in PrEP uptake have been observed among gay, bisexual, and other men who have sex with (MSM) in California.