Back HIV Prevention Pre-exposure (PrEP) Many More Could Benefit from HIV PrEP, But Not Enough Doctors Are Aware

Many More Could Benefit from HIV PrEP, But Not Enough Doctors Are Aware


One-quarter of gay and bisexual men in the U.S. and one-fifth of people who inject drugs, but less than 1% of heterosexual men and women, could benefit from Truvada pre-exposure prophylaxis or PrEP -- more than 1.2 million people in total -- according to a new Centers for Disease Control and Prevention (CDC) Vital Signs report released ahead of World AIDS Day. But a nationwide survey found that one-third of U.S. healthcare providers had not heard about PrEP, prompting the CDC to launch an expanded awareness effort.

"PrEP has the potential to dramatically reduce new HIV infections in the nation," said Jonathan Mermin, director of CDC’s National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention. "However, PrEP only works if patients know about it, have access to it, and take it as prescribed."

How Many People Could Benefit from PrEP?

The U.S. Food and Drug Administration approved Gilead Sciences' Truvada (tenofovir/emtricitabine) for PrEP in July 2012. In May 2014 the CDC recommended that people at substantial risk for HIV infection should consider PrEP.

The new analysis by Dawn Smith and colleagues from the CDC, published in the November 27 edition of Morbidity and Mortality Weekly Report, looked at nationally representative data from the National Health and Nutrition Examination Survey (NHANES 2007-2008, 2009-2010, and 2011-2012) to estimate the number of adults (age 18-59) who are at substantial risk for HIV infection consistent with PrEP indications in the 2014 U.S. Public Health Service's PrEP clinical practice guideline.

According to the guidelines, those at high risk include HIV-negative sexually active gay and bisexual men who have anal sex without condoms with an HIV-positive partner, a partner whose HIV status is unknown, or multiple sex partners, as well as those with recent sexually transmitted infections. For people who inject drugs, PrEP is indicated for those who share needles or other drug injection equipment, have recently undergone drug treatment using methadone or buprenorphine, or are at risk for infection via sex. Heterosexuals at risk include those who do not always use condoms with an HIV-positive partner, a partner of unknown HIV status, partners who inject drugs, or (for women) behaviorally bisexual men.


  • Approximately 1 in 4 sexually active gay and bisexual men (24.7%) are at substantial risk for HIV, for a total of 492,000.
  • Nearly 1 in 5 people who inject drugs (18.5%) are at risk, for a total of 115,000.
  • 1 in 200 heterosexual adults (0.4%) are at risk, for a total of 624,000.
  • Among the heterosexuals, about 3 times more women are at risk than men (468,000 vs 157,000).
  • Overall, an estimated 1,232,000 adults in the U.S. have substantial risk for acquiring HIV infection.

PrEP approval was based in part on data from the iPrEx trial of mostly gay and bisexual men, which showed that daily Truvada reduced the risk of HIV infection by 42% overall, rising to 92% among participants with blood drug levels indicating regular use; in an open-label extension of iPrEx, none of the men who took Truvada at least 4 times a week became infected. A more recent iPrEx analysis found that PrEP appears to work for transgender women if taken consistently. Similarly, the U.K. Proud and French Ipergay studies found that either daily or "on demand" PrEP reduced the risk of infection among gay men by 86%.

Research on other populations has been less extensive and the results less consistent. Truvada reduced the risk of HIV infection among heterosexual couples by approximately 75% overall in thePartners PrEP and TDF2 studies, but the Fem-PrEP and VOICE trials of at-risk African women were unable to show a protective effect due to limited adherence. Consistent use of tenofovir alone was associated with about a 50% overall reduction in the risk of infection among injection drug users in the Bangkok Tenofovir Study, rising to 70% among those with good adherence.

"Based on current guidelines, many [men who have sex with men], persons who inject drugs, and heterosexually active adults have indications for PrEP," the CDC study authors concluded. "Efforts to increase knowledge of and access to PrEP should accompany efforts to increase early diagnosis and treatment of persons with HIV infection to achieve the prevention benefits of viral suppression."

"PrEP isn't reaching many people who could benefit from it, and many providers remain unaware of its promise," said CDC Director Tom Frieden said during a November 24 media briefing announcing the findings. "With about 40,000 HIV infections newly diagnosed each year in the U.S., we need to use all available prevention strategies."

Improving Access to PrEP

Although primary care providers should be qualified to provide PrEP, an unpublished 2015 national survey of U.S. healthcare providers found that 34% had not heard of PrEP, according to the report. While the survey suggests that two-thirds of providers are at least familiar with PrEP, that does not necessarily mean they are comfortable providing it, CDC principal deputy director Ann Schuchat told reporters. "The bottom line is doctors need more prep about PrEP."

"Clinicians are key to increasing awareness of PrEP, and you can discuss HIV risk with all patients to better identify those who would benefit," Mermin stated in a CDC video addressing providers. "Any prescribing healthcare provider can deliver PrEP care. You have the power to protect your patients from HIV by assessing their risk from sex and drug use behaviors and offering PrEP to patients with the recommended indications."

It has been difficult to get a handle on how many people have received PrEP to date. A survey covering about 40% of U.S. pharmacies by Truvada manufacturer Gilead Sciences found that more than 8500 individuals have been prescribed Truvada presumably for PrEP (that is, not with other antiretrovirals, as it would be used for HIV treatment) since the beginning of 2012. However, this is an underestimate as it does not include people receiving PrEP through clinical trials, demonstration projects, Medicaid, Gilead's patient assistance program, or non-reporting health facilities such as Kaiser Permanente. Altogether, experts estimate that the total number of people on PrEP may reach at least 25,000.

Concerted efforts could substantially increase the number of people with access to PrEP, according to a second analysis also published in the November 27 edition of MMWR.

Franklin Laufer and colleagues with the New York State Department of Health looked at changes in PrEP use after the governor adopted a plan to end the AIDS epidemic in June 2014.

The plan includes an effort to increase knowledge about PrEP, train providers, and ensure Medicaid coverage. Approximately 3000 new cases of HIV infection occur in New York State each year, the authors noted as background, and about a quarter of state residents are covered by Medicaid.

The researchers found that the number of New York residents on Medicaid who filled prescriptions for Truvada for PrEP increased by more than 300% -- or more than 4-fold -- rising from 259 during July 2012-June 2013 and 303 during July 2013-June 2014, to 1330 during July 2014-June 2015.

Across all periods a total of 1708 Medicaid recipients filled at least 1 prescription for PrEP. Overall, nearly two-thirds were men (rising to 78% during the latter period), about half of those with available race/ethnicity data were white (rising to 66% during the latter period), more than 85% were under age 50, and most (81%) lived in New York City.

"PrEP use by Medicaid-insured persons increased substantially in the years following statewide efforts to increase knowledge of PrEP among potential prescribers and candidates for PrEP," the authors concluded. "Other jurisdictions can follow New York State's example by taking similar steps to remove the financial and knowledge barriers experienced by both potential users and prescribers of PrEP."

However, they added,"Although the increase in percentage of Medicaid recipients filling Truvada prescriptions for PrEP…is substantial, the number of persons doing so remains low relative to the number needed to treat in order to achieve the goals of New York state's Ending the AIDS Epidemic initiative."

One Tool Among Many

The CDC has taken a number of steps to expand awareness of and access to PrEP, agency officials explained during the media briefing, including tools to help healthcare providers counsel patients and evaluate who is eligible for PrEP.

The latest update to the National HIV/AIDS Strategy includes PrEP as a key focus of a high-impact prevention effort, along with HIV testing, linkage to care, early antiretroviral treatment, and support to help people with HIV remain in care and maintain good adherence in order to achieve viral suppression.

In March the CDC announced that it is awarding up to $125 million in HIV prevention funding over 3 years to state and local health departments, and in July it announced another $216 million to be granted over 5 years to 90 community-based organizations to increase access to PrEP and other prevention services for people at greatest risk, including gay men, transgender women, and people who inject drugs.

But CDC officials stressed that while PrEP is a good tool for the right people, all prevention strategies must be used to have the greatest impact, including widespread HIV testing, suppressive antiretroviral therapy for people living with HIV, use of condoms, and availability of sterile drug injection equipment.

"In a highly complex HIV prevention landscape, PrEP can help fill gaps, but no one intervention will end the HIV epidemic -- we must use all the tools," Mermin told reporters. "Suppressive treatment can prevent transmission, but only about 30% of Americans with HIV have their virus suppressed."

Schuchat acknowledged that PrEP can be expensive -- about $10,000 per year -- but payment assistance is available for low-income people and Medicaid and most private insurers will cover the cost. "It is a recommended intervention that we think is very effective -- it is much less expensive to prevent HIV than to have a lifetime of healthcare costs," she said.

"Science clearly calls out to us that PrEP works," Mermin added. "The lives of Americans are too important for us not to get PrEP to people who need it."



DK Smith, M Van Handel, RJ Wolitski, et al. Vital Signs: Estimated Percentages and Numbers of Adults with Indications for Preexposure Prophylaxis to Prevent HIV Acquisition -- United States, 2015. Morbidity and Mortality Weekly Report 64(46):1291-1295. November 27, 2015.

FN Laufer, DA O'Connell, I Feldman, and HA Zucker. Vital Signs: Increased Medicaid Prescriptions for Preexposure Prophylaxis Against HIV Infection -- New York, 2012-2015. Morbidity and Mortality Weekly Report 64(46):1296-1301. November 27, 2015.

Centers for Disease Control and Prevention. New CDC estimates underscore the need to increase awareness of a daily pill that can prevent HIV infection. Press release. November 24, 2015.

Centers for Disease Control and Prevention. Daily Pill Can Prevent HIV Infection. Vital Signs. November 24, 2015.