Careteam, a South Carolina AIDS service organization, is teaming with the Rape Crisis Center to provide post-exposure prophylaxis (PEP) treatment and follow-up care to women who have been victims of sexual assault to prevent possible transmission of HIV, The Sun News/Myrtle Beach Online reports.

According to officials, most women’s insurance companies do not cover the cost of PEP medications, which many women cannot afford otherwise. Beginning the short-term antiretroviral treatment within 72 hours of possible exposure can prevent HIV infection from taking place.

“One of the issues with rape victims who don’t know their assailants is that they are at high risk of exposure to HIV,” said Johanna Haynes, Careteam’s executive director. “The medication is not easy to take, and it is not affordable for women. You have women walk out with the prescription, but never get it filled.”

Careteam—which provides services to people living with or affected by HIV in Horry, Georgetown and Williamsburg counties—must hold fundraisers to cover the cost of PEP, which is not covered by federal or other grants the organization receives. A 28-day supply of the medication costs $1,200.

According to the Rape Crisis Center, 246 people—mostly women—have been sexually assaulted by strangers in Horry and Georgetown counties in the past three years compared with 898 during that time frame who knew their attackers.