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Cross-posted from NIAID Newsroom
Today marks the 30th celebration of World AIDS Day. Three decades ago, the HIV/AIDS pandemic looked very different than it does today. While AIDS had been part of our lives since 1981, the tools to fight the disease during that period were still inadequate, despite robust research efforts. Although the licensure in 1987 of AZT—the first antiretroviral medication to treat HIV—had been an important development, it soon became clear that the drug had only a limited and transient benefit. Prevention options were limited to basic “low-tech” tools such as condom use, needle exchange and behavioral modification. However, it was clear that we needed to do better.
Over the subsequent years, through an accelerated research effort, scientists created an array of new antiretroviral treatments that targeted several vulnerable functions in the replication cycle of the virus. When used in combinations, these drugs durably suppressed the replication of the virus. Over the years, drug regimens became even more powerful with fewer side effects. Today, therapies can allow a person living with HIV to achieve a nearly normal lifespan, and some regimens require only one pill once a day. In addition, landmark studies of antiretrovirals in pregnant women living with HIV showed that these drugs can prevent perinatal transmission of the virus.
Antiretrovirals have the capability of both treating HIV infection in an individual and preventing the transmission of the virus to another. Numerous studies have demonstrated that when a person living with HIV uses antiretroviral therapy to achieve and maintain a durably undetectable level of virus, he or she has effectively no risk of sexually transmitting HIV. For HIV-negative people, taking a single pill daily as pre-exposure prophylaxis, or PrEP, can reduce the risk of acquiring HIV by more than 90 percent. Emergency post-exposure prophylaxis, or PEP, can prevent HIV from establishing itself in the body if begun within three days of exposure and taken for an additional 28 days.
We have seen how lifesaving antiretroviral treatment can change the course of HIV disease in individual patients. It also can change the trajectory of the epidemic in communities, particularly when combined with other advances in HIV prevention. We see this change in communities that are precisely applying these interventions to dramatically decrease the incidence of new infections. A study published recently in the New England Journal of Medicine found that HIV incidence dropped by 42 percent among nearly 18,000 people in a Ugandan district during a 7-year period when the rates of HIV treatment and voluntary medical male circumcision were significantly increased.
If our current arsenal of treatment and prevention tools could be widely implemented, an end to the HIV/AIDS pandemic theoretically would be feasible. Realistically, however, we will need new and improved tools for our HIV treatment and prevention armamentarium along with implementation of new and existing approaches to end the HIV pandemic as we know it.
Adherence to once-daily therapeutics and PrEP can be challenging, and so researchers are investigating longer-acting formulations of these products that some people may find easier to use. A trial testing long-acting injectable cabotegravir for PrEP in women has launched in southern Africa, and the same drug currently is under investigation for men. Additional injectable and implantable formulations are in the research “pipeline,” providing hope that prevention and treatment could be delivered as infrequently as quarterly or even twice a year.
Other studies are testing the passive transfer of broadly neutralizing antibodies for preventing HIV infection. The results of these studies will inform HIV prevention and vaccine efforts. Earlier this year, NIAID’s Vaccine Research Center, together with partners from Sanofi, developed a novel, three-pronged antibody that protected against HIV-like infections in preclinical studies and is moving into clinical testing. Harnessing the power of antibodies holds great promise for developing new long-acting HIV prevention and treatment tools.
The ultimate goal for HIV prevention is development of a safe and effective vaccine. The National Institutes of Health announced yesterday that a new Phase 2b, proof-of-concept trial of an HIV vaccine has been launched in southern Africa. The study, called Imbokodo (HVTN 705), aims to enroll 2,600 HIV-negative women in sub-Saharan Africa. This new trial joins HVTN 702, a Phase 2b/3 vaccine efficacy trial being conducted in South Africa, aiming to build on the modest results of the RV144 vaccine trial in Thailand.
As the HIV prevention and treatment “toolkits” have matured, NIH has taken steps to ensure that all people can benefit from these advances. Transgender women—people whose birth certificates indicate or once indicated male sex but who identify as women—are at high risk of HIV infection, and are a key population for HIV prevention and treatment efforts. A recent study of transgender women living with HIV in Los Angeles found a majority were concerned about drug interactions when taking both antiretroviral therapy and feminizing hormone therapy. Little is known about this issue, and NIH is working to fill these knowledge gaps.
Pregnancy and infancy pose unique challenges to preventing HIV transmission and maintaining health. While safe and effective antiretroviral regimens have been developed for preventing perinatal transmission, further studies need to be performed to ensure that pregnant women and their infants can safely use newer forms of these medications. NIH plans to soon launch a large international study to compare the safety and efficacy of three antiretroviral treatment regimens for pregnant women living with HIV and to determine the safety of these regimens for their infants. This week, the U.S. Food and Drug Administration extended its approval [PDF, 76 KB] for the integrase inhibitor raltegravir for younger infants based on data from the NIAID-funded IMPAACT P1110 study. The drug is now approved for use in infants at birth.
After 30 years of marking progress against HIV with the observance of World AIDS Day, we are closer than ever to the beginning of the end of the HIV/AIDS pandemic. Science has delivered numerous tools and holds promise for additional options, yet implementation of these tools remains paramount. We must increase our efforts to deliver effective treatment and prevention strategies to those who need them. We thank and applaud the many clinical trial participants, researchers, health care professionals, advocates and others who are working to prevent new infections and improve the health of those living with HIV worldwide. We look forward to working across NIH with all the Institutes and Centers engaged in HIV and related research to ensure that scientific progress against the pandemic is maximized and that we do not lose what we have gained.
NIAID conducts and supports research—at NIH, throughout the United States, and worldwide—to study the causes of infectious and immune-mediated diseases, and to develop better means of preventing, diagnosing and treating these illnesses. News releases, fact sheets and other NIAID-related materials are available on the NIAID website.
The Office of AIDS Research (OAR) coordinates the NIH HIV research investment across all 27 Institutes and Centers. More information on OAR is available on the OAR website.
About the National Institutes of Health (NIH): NIH, the nation’s medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit www.nih.gov.