National and global efforts to reduce HIV transmission through prevention and treatment-as-prevention just received a boost from the World Health Organization (WHO). In late September, WHO recommended that anyone with HIV begin antiretroviral therapy (ART) as soon as possible after first diagnosis and that anyone with high-risk factors have access to pre-exposure prophylaxis (PrEP) to prevent new infection -- and HIV organizations and advocates took to social media to show their support. These early-release recommendations precede comprehensive revised guidelines to be published early next year. WHO made the early-release version available due to the potential for an immediate positive impact on global health. WHO continues to recommend other measures for prevention and treatment, including HIV testing, counselling and support, and access to condoms and safe injection equipment.
Previous WHO guidelines recommended ART for any HIV-positive individual with a CD4 count less than 350 cells/mm3. WHO estimates that as a result of the new recommendation the number of people eligible globally for ART is now approximately 37 million -- an increase of nine million worldwide from the previous guidelines.
The recent Strategic Timing of AntiRetroviral Treatment (START) study, a large-scale randomized clinical trial, established that early ART not only has positive outcomes for all people with HIV, but also significantly reduces infectiousness and thus the risk of transmission. This addresses the need to reduce HIV transmission between serodiscordant (positive and negative) sexual and drug-using partners, including during acute HIV infection in the infected partner. Acute HIV infection takes place two to four weeks after initial transmission of the virus. During this period, large amounts of the virus are present in the bloodstream, which greatly increases the risk of transmission.
The new guideline for PrEP expands on WHO's 2014 recommendation to make PrEP, currently available only in the form of Truvada (tenofovir/FTC), readily available to men who have sex with men (MSM). Mounting evidence, including the results to date from San Francisco's Kaiser Permanente Medical Center's PrEP program, indicates that PrEP has a high effectiveness rate. Kaiser Permanente reported in July that the Center had no new HIV diagnoses for two and a half years among PrEP users in the program. These findings have contributed to WHO's expanded recommendation to "support the offer of PrEP" not only to MSM, but also "to other population groups at significant HIV risk." Importantly, a recently completed study by the National Institutes of Health found that the majority of MSM and transgender women participants adhered to PrEP most of the time, allaying some community concerns about the probability of PrEP adherence, which is necessary for peak effectiveness.
HIV organizations and advocates expressed their support for the WHO recommendations on social media, including Twitter: