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For HIV, Treatment is Prevention

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U=U

For almost four decades, researchers have worked tirelessly to find a cure for the human immunodeficiency virus (HIV), which causes AIDS. There’s still more work to do, but a recent commentary published in JAMA [1] by Anthony Fauci, director of NIH’s National Institute of Allergy and Infectious Diseases, and his colleagues serves as a reminder of just how far we’ve come. Today, thanks to scientific advances, especially the development of effective antiretroviral therapy (ART), most people living with HIV can live full and productive lives. These developments have started to change how our society views HIV infection.

In their commentary, the NIH scientists describe the painstaking research that has now firmly established that people who take ART daily as prescribed, and who achieve and maintain an undetectable viral load (the amount of HIV in the blood), cannot sexually transmit the virus to others. To put it simply: Undetectable = Untransmittable (U=U).

The U=U message was introduced in 2016 by the Prevention Access Campaign, an international health equity initiative that aims to help end the HIV epidemic and HIV-related social stigma. The major breakthrough in combination ART regimens, which successfully reduced viral loads for many HIV patients, came over 20 years ago. But their importance for HIV prevention wasn’t immediately apparent.

There’d been some hints of U=U, but it was the results of the NIH-funded HIV Prevention Trials Network (HPTN) 052, published in The New England Journal of Medicine [2] in 2011, that offered the first rigorous clinical evidence. Among heterosexual couples in the randomized clinical trial, no HIV transmissions to an uninfected partner were observed when ART consistently, durably suppressed the virus in the partner living with HIV.

The data provided convincing evidence that ART not only treats HIV but also prevents the sexual transmission of HIV infection. The public health implications of what’s sometimes referred to as “treatment as prevention” were obvious and exciting. In fact, the discovery made Science’s 2011 list of top 10 Breakthroughs of the Year .

Three subsequent studies, known as PARTNER 1 and 2 and Opposites Attract, confirmed and extended the findings of the HPTN 052 study. All three showed that people with HIV taking ART, who had undetectable HIV levels in their blood, had essentially no risk of passing the virus on to their HIV-negative partners.

Of course, the success of U=U depends on people with HIV having the needed access to health care and taking their medications as prescribed every day of their lives [3]. ART works by preventing the virus from making more copies of itself. It’s important to note that achieving an undetectable viral load with treatment can take time—up to 6 months. Viral load testing should be performed on a regular basis to ensure that the virus remains at undetectable levels. If treatment is stopped, the virus typically rebounds within a matter of weeks. So, strict adherence to ART over the long term is absolutely essential.

Practically speaking, though, ART alone won’t be enough to end the spread of HIV, and other methods of HIV prevention are still needed. In fact, we’re now at a critical juncture in HIV research as work continues on preventive vaccines that could one day bring about a durable end to the pandemic.

But for now, there are more than 35 million people worldwide who are HIV positive [4]. With currently available interventions, experts have predicted that about 50 million people around the world will become HIV positive from 2015 to 2035 [5]. Work is proceeding actively on the vaccine, and also on ways to totally eradicate the virus from infected individuals (a “cure”), but that is proving to be extremely challenging.

Meanwhile, with continued advances, including improved accessibility to testing, adherence to existing medications, and use of pre-exposure prophylaxis (PrEP) in high risk individuals, the goal is to reduce greatly the number of new cases of HIV/AIDS.

References:

[1] HIV Viral Load and Transmissibility of HIV Infection: Undetectable Equals Untransmittable. Eisinger RW, Dieffenbach CW, Fauci AS. JAMA. 2019 Jan 10.

[2] Prevention of HIV-1 infection with early antiretroviral therapy. Cohen MS, Chen YQ, McCauley M, Gamble T, Hosseinipour MC, Kumarasamy N, Hakim JG, Kumwenda J, Grinsztejn B, Pilotto JH, Godbole SV, Mehendale S, Chariyalertsak S, Santos BR, Mayer KH, Hoffman IF, Eshleman SH, Piwowar-Manning E, Wang L, Makhema J, Mills LA, de Bruyn G, Sanne I, Eron J, Gallant J, Havlir D, Swindells S, Ribaudo H, Elharrar V, Burns D, Taha TE, Nielsen-Saines K, Celentano D, Essex M, Fleming TR; HPTN 052 Study Team. N Engl J Med. 2011 Aug 11;365(6):493-505.

[3] HIV Treatment (U.S. Department of Health and Human Services)

[4] HIV/AIDS (World Health Organization)

[5] Effectiveness of UNAIDS targets and HIV vaccination across 127 countries. Medlock J, Pandey A, Parpia AS, Tang A, Skrip LA, Galvani AP. Proc Natl Acad Sci U S A. 2017 Apr 11;114(15):4017-4022.

Links:

HIV/AIDS (National Institute of Allergy and Infectious Diseases/NIH)

Treatment as HIV Prevention (NIAID)

Prevention Access Campaign

Anthony S. Fauci (NIAID)

HIV Prevention Trials Network (Durham, NC)


An Aspirin a Day for Older People Doesn’t Prolong Healthy Lifespan

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Hands holding a pill and a glass of water

Credit: iStock/thodonal

Many older people who’ve survived a heart attack or stroke take low-dose aspirin every day to help prevent further cardiovascular problems [1]. There is compelling evidence that this works. But should perfectly healthy older folks follow suit?

Most of us would have guessed “yes”—but the answer appears to be “no” when you consider the latest scientific evidence.  Recently, a large, international study of older people without a history of cardiovascular disease found that those who took a low-dose aspirin daily over more than 4 years weren’t any healthier than those who didn’t. What’s more, there were some unexpected indications that low-dose aspirin might even boost the risk of death.


Precision Medicine: Who Benefits from Aspirin to Prevent Colorectal Cancer?

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Aspirin and DNA StethoscopeIn recent years, scientific evidence has begun to accumulate that indicates taking aspirin or other non-steroidal anti-inflammatory drugs (NSAIDs) on a daily basis may lower the risk of developing colorectal cancer. Now, a new study provides more precise information on who might benefit from this particular prevention strategy, as well as who might not.

Published in the journal JAMA, the latest work shows that, for the majority of people studied, regular use of aspirin or NSAIDs was associated with about a one-third lower risk of developing colorectal cancer. But the international research team, partly funded by NIH, also found that not all regular users of aspirin/NSAIDs reaped such benefits—about 9 percent experienced no reduction in colorectal cancer risk and 4 percent actually appeared to have an increased risk [1]. Was this just coincidence, or might there be a biological explanation?