Abstract Despite the availability of effective HIV prevention tools such as pre-exposure prophylaxis (PrEP), significant disparities persist among communities of color, particularly among women in the Deep South where the rate of HIV diagnosis is fourteen-times higher for Black women compared to White women. Current literature supports that alcohol use is associated with condomless sex and increased number of sexual partners, which may predict greater likelihood of STI/HIV acquisition among Southern Black women. The proposal takes advantage of a dynamic and innovative collaboration of experienced HIV-prevention investigators from the University of Alabama-Birmingham, University of North Carolina-Chapel Hill, Centers for AIDS Research, and the Alabama Department of Public Health (ADPH). In the parent Camellia Cohort, a population-based approach is used to establish a geographically representative cohort of cis- and trans-gender women (‘Camellia Cohort,’ N = 800) at significant risk for future HIV acquisition, based on recent gonorrhea or syphilis infection, across the state of Alabama (AL), highlighted as a geographic hotspot by the federal Ending the HIV Epidemic strategy, to better understand factors associated with risk of STI and HIV diagnosis and predictors for PrEP use. Leveraging current enrollment into this cohort, we will recruit a subset of women to assess the following aims: 1) describe subjective and objective measures of alcohol use in a cohort of women vulnerable to HIV and living in AL by consenting 200 women form our parent study to self-collect alcohol biomarkers; 2) evaluated the association of objectively measured alcohol use with a) incidence of STI and b) PrEP uptake and 3) explore the acceptability and feasibility of biomarker evaluation among a cohort of women vulnerable to HIV by interviewing women who consented to enroll in the supplemental study and those who did not (n = 12, each arm). Study findings will provide updated estimates of how alcohol use impacts health outcomes and HIV prevention behaviors while also providing critical information regarding how best to collect these data from women. Our data measures will harmonize measures across the AWARE-funded projects providing the opportunity to provide data for community partners launching initiatives to promote a reduction in HIV/STI incidence.