NIAID director Dr. Anthony S. Fauci stresses in a recent commentary that, from a practical standpoint, the development of a moderately effective HIV vaccine is “essential” to ending the pandemic.
Several advancements have been made in the fight against HIV, however, the pandemic persists. The treatment and prevention options that are available are very effective if adhered to, but are they enough to stop the pandemic?
In a recent commentary, Anthony S. Fauci, MD, director of the National Institute of Allergy and Infectious Diseases (NIAID), says that from “a practical standpoint,” probably not. Rather, the development of a moderately effective HIV vaccine—coupled with the implementation of existing treatment and preventive modalities—is “essential” to ending the pandemic.
Dr. Fauci first shared his thoughts on this topic at the 9th IAS Conference on HIV Science (IAS 2017) in Paris, France. “Theoretically, yes. I say, ‘yes, theoretically’ because advances in HIV science over the past 35 years have been nothing short of breathtaking [in all areas], not least of which in [the area] of treatment.”
Dr. Fauci admits that theoretically, the pandemic can meet its end without the vaccine, but it’s highly unlikely and would be incredibly difficult to accomplish. With 30 “highly effective anti-HIV drugs” available, HIV-positive individuals are able to live just as long as someone who is uninfected with the virus. By adhering to a treatment regimen consisting of 3 more anti-HIV drugs, infected individuals are able to reduce their viral load low enough so that their likeliness of passing the infection on to others is “extremely unlikely.” Therefore, if everyone with HIV “could be identified, accessed, and treated, it would be possible to stop all infections and end the epidemic,” Dr. Fauci writes.
Not only have we come a long way when it comes to treating those infected, but massive strides have been made in the prevention of the virus. The biggest means of prevention? Pre-exposure prophylaxis, or a single pill that is comprised of 2 different anti-HIV drugs, that can decrease the likeliness of infection via sexual intercourse in those who are at risk by a whopping 90%—if adhered to properly.
“Accordingly, if both of these treatment and prevention modalities were effectively implemented throughout the world, the HIV/AIDS pandemic would end,” Dr. Fauci admits. However, it’s unlikely that the pandemic can be brought to an end without a vaccine. He points out, “Although an estimated 19.5 million of the estimated 36.7 million HIV-infected people globally are receiving anti-HIV therapy (an extraordinary accomplishment), more than 17 million people are not receiving therapy. This leaves a substantial treatment gap.” Those who are not on treatment are likely to pass the infection onto others, thus keeping the pandemic going.
He also points out that although PrEP has proven highly effective, “only a very small percentage of these individuals are actually taking these medications.” In fact, in the United States, it is estimated that only 10% of those who should be receiving PrEP are actually doing so; the percentage is even lower in other countries.
In his commentary, Dr. Fauci also explores whether ending the pandemic without a vaccine is “economically feasible.” His deduction? No, for a number of reasons. For one, the resources required to keep those on anti-HIV drugs for the rest of their lives, are increasing. The 17.2 million infected individuals who are not receiving treatment, will also need to be put on medication. He also adds, “The cost of providing PrEP and other preventive services to the millions of people who are at risk for HIV infection is substantial.” In fact, UNAIDS estimated that to provide effective treatment and prevention response from 2016 to 2030 in low- and middle-income countries would be incredibly costly—adding up to at least $350 billion. Dr. Fauci cites another study that found that “donor-government funding” dedicated to HIV has actually decreased by 7% in 2016, “the lowest funding level since 2010.”
“That then allows me to come to a conclusion that we will actually need an HIV vaccine to achieve—and I want to underscore a very important word—a durable end to the HIV pandemic. So, I’m not saying that we’re not going to make major strides in getting the trajectory down, but will it stay down given all of the constraints that we see without a vaccine?” Dr Fauci asked in his presentation at IAS 2017.
A large HIV vaccine trial that had been conducted in Thailand found that the vaccine was capable of decreasing risk of infection by 31%, “a figure inadequate to justify the licensure of the vaccine.” This finding is not entirely unsurprising. In fact, Dr. Fauci predicts that a future HIV vaccine will not be as effective as the other vaccines currently available for other infectious diseases, such as smallpox and yellow fever, vaccines that are estimated to be almost 100% effective. Why? Because it is extremely difficult for the human immune system to “mount a protective response against HIV,” he stated. Nonetheless, a vaccine that decreases risk by at least 50% is needed, he writes.
Dr. Fauci stresses that the vaccine alone does not hold the answer to ending the pandemic. The development of a moderately-effective vaccine “together with the optimal implementation of existing treatment and prevention modalities” are capable of ending the ongoing pandemic.
“It is critical to continue to accelerate a robust research effort in that direction while aggressively scaling-up the implementation of current treatment and prevention tools,” Dr. Fauci concluded. “To do anything less would lead to failure, which for HIV is not an option.”