Striving for the AIDS End Game: Translating Research Promise Into Public Health Success
We can reduce and move toward elimination of new infections with the expanded combination prevention "tool kit" that biomedical research and public health practices have provided. When HIV transmission was first understood, public health prevention messages were limited for the most part to promotion of condom usage and safe injection practices. Today, expectant HIV-infected mothers can virtually eliminate the risk of transmission to their newborns with proper use of antiretroviral medications. In this regard, antiretroviral treatment lowers HIV burden to extremely low levels; among heterosexual partners in which one partner is infected and the other is not, early treatment of the infected partner has been shown to reduce the risk of HIV transmission to uninfected sexual partners by 96 percent. At-risk uninfected individuals can protect themselves from HIV infection using pre-exposure prophylaxis, whereby individuals take a daily antiretroviral therapy pill to prevent infection. Another strategy is built on the observation that circumcised men had lower rates of HIV than uncircumcised men, and clinical trials and real world studies of voluntary adult male medically-supervised circumcision have demonstrated a 50-75 percent reduction in the risk of infection among circumcised men that has been sustained over several years. These prevention tools, combined with public health programs that promote their acceptance and adherence can substantially reduce new infections. However, failure of these two latter factors often creates stumbling blocks in achieving maximal effectiveness.
The global AIDS community must better understand the social factors that drive individual acceptance of and adherence to prevention modalities and treatment. Specifically, in addition to a nuanced understanding of financial and cultural barriers to care, stigma and discrimination must be systematically addressed. For example, in certain settings in the United States, condoms are used by law enforcement officials as forensic evidence of commercial sex work, complicating promotion of safe sex. Around the world, homosexuality is illegal in 76 countries and highly stigmatized in many more. These egregious examples of institutional discrimination, and the individual discrimination that invariably accompanies it, must be eliminated.
Although existing prevention methods paired with stigma reduction can help reduce new infections, these gains must be sustained for generations to come. To accomplish this, an HIV vaccine remains an important tool. Vaccination offers the ability to prevent infection at the population level without reliance on continual adherence to interventions at the individual level. Thus, pursuit of a vaccine remains a top priority for the scientific and global health community. Following years of disappointments, a large clinical trial in Thailand showed a 31 percent reduction in infection among vaccinated people. This response was encouraging, but recent scientific advances indicate that more robust results may be possible. Specifically, new insights into broadly neutralizing antibodies that powerfully block HIV entry into cells and into more effective cellular immune responses have reinvigorated the quest for an HIV vaccine. With the promise of such advances and other prevention tools available today, the rate of new HIV cases can be dramatically reduced, and hopefully ultimately eliminated.
Even if incidence of new infections is dramatically reduced, the global AIDS response must continue to address the needs of the 35.3 million individuals living with HIV/AIDS around the world. A handful of recent cases have highlighted the possibility of "cure," or sustained remission, whereby patients can control or perhaps even eliminate HIV without daily drug therapy. Notwithstanding the possibility of therapy-free sustained remissions, disease progression can largely be stopped with existing antiretroviral drugs widely available today. In other words, by treating individuals, the global AIDS community can strive toward the elimination of AIDS morbidity and mortality. To do so, availability of effective antiretroviral therapy must be expanded in accordance with the World Health Organization's treatment guidelines, which will require bolstering of human and financial resources, paired with implementation expertise. Gaps must be closed in the care continuum from diagnosis, to entry into health care, to retention in care, and to initiation and maintenance of treatment. Issues related to access to and delivery of health care, as well as social, behavioral and economic factors (among others) need to be addressed as well. In addition, the long-term comorbidities of HIV infection, i.e., associated diseases that are more frequent, premature, and/or serious in HIV-infected individuals, must be better understood and addressed.
Finally, to control this epidemic and strive toward its end, effective interventions must be paired with political will and economic resources. The President's Emergency Plan for AIDS Relief, the Global Fund to Fight AIDS, Tuberculosis & Malaria, the Bill & Melinda Gates Foundation, the Clinton Health Access Initiative and other programs have made remarkable strides in fighting HIV/AIDS by smartly investing dollars in targeted, proven interventions, and working with partners at the international, regional, national and local levels around the world. These programs save lives -- according to UNAIDS, from 1995 to 2012, antiretroviral therapy averted 6.6 million AIDS-related deaths worldwide, including 5.5 million deaths in low- and middle-income countries.
The collective efforts of health care practitioners, patients and researchers around the world have brought new promise to the decades-long fight against HIV/AIDS. By sustaining and accelerating this fight, and striving toward the "end of AIDS," lives can be saved and suffering averted for decades to come.