Democratic presidential candidate Sen. Kamala Harris (D-Calif.) introduced a bill on Thursday that would make a highly effective but underused anti-HIV drug more accessible, tackling both its cost and the stigma it carries.

Harris’ bill focuses on expanding access to pre-exposure prophylaxis, or PrEP, a medication that dramatically lowers the risk of contracting HIV for people at high risk for the infection. The bill would ease the financial burden on consumers by guaranteeing the pill is fully covered by private insurance, Medicaid and Medicare and would allocate resources to cover uninsured patients. It would also ban companies selling life, disability and long-term insurance from denying coverage or charging higher premiums to people taking PrEP.

The bill would also address the stigma associated with PrEP by funding a public education campaign on the pill, highlighting its effectiveness and safety.

“PrEP is a critical advancement in the fight against HIV that can finally provide peace of mind to Americans who live in the shadow of the HIV epidemic,” Harris said in a statement. “But for too many in our country, lack of insurance coverage and exorbitant costs have put PrEP out of reach ― and that needs to change.”

PrEP is highly effective. Consistent use of PrEP by people at high risk for HIV has been shown to reduce their risk of contracting the disease by up to 92%, according to the Centers for Disease Control and Prevention.

But it can be prohibitively expensive. A 30-day supply of Truvada, a brand-name PrEP pill, costs $2,000 ― a price that has risen in the last few years. In 2018, Truvada cost over $20,000 per year. And while most insurers do cover the pill, they don’t cover it all the way.

HIV is sometimes more prevalent in communities with less health care, according to Trevor Hart, director of the HIV Prevention Lab and a professor in the Department of Psychology at Ryerson University in Toronto.

Harris’ bill would “equal the playing field,” Hart said. “And, [it] hopefully would allow people who are lower income to have better access to the medication.”

PrEP use among gay and bisexual men who are at risk of HIV infection has risen in the past few years: It surged from only 6% in 2014 to 35% in 2017, according to a CDC study presented in 2019. Some 90% of the 8,000 men interviewed for the study knew about PrEP, with awareness almost 10% higher among white men than African American and Latino men. (The study focused on gay and bisexual men, although PrEP can also be taken by anyone who is at high risk of HIV.)

Put simply, more people know about the highly effective pill than are choosing to take it. The pill is underutilized, the study concluded.

And its use is marked by a stark racial divide: While 42% of white gay and bisexual men use PrEP, just 26% of African American men do.