Colleen Kelley

Politics, funding declines, and diminished focus on HIV as a priority are global obstacles to reducing HIV incidence, and implementation of prevention interventions must fight an uphill battle. This session discussed scientific advances in understanding HIV acquisition, scale-up of biomedical prevention, and barriers to reaching at-risk individuals in unstable environments.

Effective HIV prevention interventions must target the earliest time points around exposure. Inflammation and immune activation in mucosal tissues are key mediators of HIV acquisition, and the vaginal microbiota is a key player in this relationship. Modulation of the host mucosal immune system could be an interesting future target for prevention. At the same time, scale-up of existing HIV prevention interventions must incorporate combination approaches: biomedical, structural, and behavioral interventions to achieve reductions in incidence. In resource rich settings, large scale implementation of PrEP and utilization of molecular epidemiology have contributed to reductions in HIV incidence. Globally, interventions addressing poverty, discrimination, stigma, and human rights violations will be necessary to implement successful combination prevention interventions. Some key populations, such as people who inject drugs (PWID), are currently being left behind by current prevention programs and new efforts and resources must be devoted to ensuring PWID benefit from HIV prevention interventions.

Translation of scientific advances into successful prevention interventions that will reduce HIV incidence at the population level requires multi-level approaches. Defining factors that contribute to an individual or populations susceptibility to infection may identify new targets for intervention. In addition, understanding how people will use these interventions and how they fit into the larger context of prevention programs is essential. Finally, populations experiencing extreme marginalization cannot be left behind. Communities must be engaged and mobilized to realize large-scale HIV prevention program success.

Antonio Camiro-Zuñiga

Interventions to prevent HIV transmission can occur at many different levels, and this session demonstrated that by showcasing many of the different research targets for HIV prevention; starting all the way from the factors favoring HIV infection at a cellular level, to community-level interventions and political decisions affecting entire populations.

McKinon started with by describing the HIV-host interaction during viral transmission, highlighting that even though per coital transmission is infrequent (regardless of the type of coitus) inflammation plays a major role in reducing the infectivity threshold for sexual transmission. Brito de Mello showed data on how community-level interventions can produce drastic changes in HIV incidence rates by different interventions including expansion to access to circumcision and ART in Africa, harm reduction programs in Portugal and legalization of sex work, and including HIV(-) individuals in the continuum of care. Finally, Gelpi-Acosta delivered a passionate lecture on the status of the opioid epidemic in Puerto Rico and the concurrent HIV and HCV syndemics. She thoroughly described the causes of the epidemic and the deleterious effect of governmental neglect in the population of people who inject drugs (PWID), proposing international funding, community engagement, education programs and political activism as solutions to the problem.

There is a long way to go in HIV prevention research, targeting local inflammation and the factors favoring said inflammation shows potential as an intervention to decrease sexual transmission of HIV across all populations. Promoting community-level interventions, scaling-up human rights and decriminalizing risk behaviors hold an enormous potential to reduce incidence rates worldwide. We must take into account that political will represents the first step towards the improvement of HIV prevention in populations where a lack of governmental support or harmful policies exist.

Heleen Vermandere

During this bridging session, HIV prevention was addressed from the perspective of basic health, more particularly by indicating factors influencing HIV transmission. Furthermore, successful interventions were shared targeting biomedical, behavioral and/or structural determinants. The latter stood in sharp contrast with the lack of attention for Puerto Rican injectable drug users.

Lyle McKinnon explained how vaginal/penile inflammation increases a person’s HIV susceptibility and how this influences the impact of prevention methods: tenofovir gel does not protect women with inflammation while the protective value of male circumcision is linked with a drop in anaerobic bacteria load (i.e. less inflammation). Biomedical breakthroughs have led to reductions in HIV infections: large-scale programs offering HIV testing, ART and/or male circumcision in Uganda, Kenya and Swaziland were able to stop the expansion of the epidemic. However, interventions addressing structural and behavioral factors are equally important. In Australia, HIV prevention programs focus on easy access, peer-based health promotion and community mobilization leading to 92-97-95+ result. The HIV epidemic among injectable drug users in Portugal was addressed by tackling drug related risks. Puerto Rican drug users however have little or no access to prevention programs due to a lack of government involvement.

Rectal acquisition is less well understood but the pathway might be similar to vaginal and penile infections: certain microbiota might induce inflammation and thus increase susceptibility. In general, reducing inflammation might help lowering the incidence of HIV. Translating research into successful preventive programs remains challenging and there is an urgent need to close the gap between medical progress and vulnerable, hard-to-reach people. Health inequality can further increase if interventions don’t take into account structural, historical and social contexts. Initiatives need to be backed by policy makers and need to be embedded in the community.