Treatment as Prevention: Concepts and Challenges for Reducing HIV Incidence

Abstract

Background: Four of the largest HIV prevention trials have been conducted in sub-Saharan Africa, enrolling hundreds of thousands of participants in catchment areas of millions of people. The trials have focused on community-level interventions to increase diagnosis and initiation of antiretroviral therapy (ART) in order to improve health and reduce HIV transmission. Universal test-and-treat strategies are deployed to achieve viral suppression thereby reducing risk to uninfected persons, known as treatment-as-prevention (TasP). Purpose: We review the work that found HIV plasma load to correlate with transmission risk, demonstrated that ART could reduce genital tract viral expression, and showed early treatment to be beneficial for persons living with HIV and that HIV-uninfected sexual partners were protected from infection. We review the seemingly inconsistent findings of the major TasP trials: The TasP (ANRS 12249) study in South Africa, the SEARCH trial in Kenya and Uganda, the Botswana Combination Prevention Project (BCPP) Ya Tsie study, and the HIV Prevention Trials Network (HPTN) 071 (PopART) trial in Zambia and South Africa. Findings: All the trials reinforce the critical need to identify approaches to optimize programs and incentivize uptake and engagement in HIV testing and ART-based care in ways that consistently reduce HIV transmission. That other chronic conditions can be screened for and treated in the same infrastructures suggests added value of HIV investments. Conclusion: Implementation challenges are a principal frontier in the global struggle to reduce HIV transmission and mortality using TasP, complementing efforts to find a cure for HIV and an effective, deployable vaccine.

Rilpivirine and Etravirine resistance among HIV-1 infected patients failing first generation non-nucleoside reverse transcriptase inhibitors (NNRTIs) in Busia, Western Kenya

“…Globally, there has been a concerted effort to scale up the provision of antiretroviral therapy (ART) (Aung et al, 2018;Dokubo et al, 2014) especially following the recent findings showing that ART is important in decreasing HIV transmission rates under the framework of HIV Treatment as Prevention (TasP) in different settings (Brault et al, 2019(Brault et al, , 2020Girum et al, 2018;Montaner et al, 2014;Osler et al, 2018). There has been a massive scale-up of antiretroviral therapy (ART) treatment and the associated services in sub-Saharan Africa in the past decade (Kharsany and Karim, 2016;Vandormael et al, 2019) to reduce AIDS-related mortality and morbidity as well as prevent HIV transmission and hence reducing its prevalence (Kharsany and Karim, 2016;Montaner et al, 2014;Osler et al, 2018).…”

The effect of 90-90-90 on HIV-1 incidence and mortality in eSwatini: a mathematical modelling study

“…3 Whether the continued expansion of treatment targets will be enough to achieve epidemic control remains unclear, given large uncertainty around the effectiveness of universal test and treat in real-world settings. 4 Universal test and treat might only suffice to stabilise or modestly reduce incidence over time in the most intense epidemics. Substantial reductions in new HIV infections have followed expanded ART coverage in some regions of east and southern Africa, 5,6 although incidence after ART scale-up has been well above predictions from previous models.…”

Tandem bispecific antibody prevents pathogenic SHIVSF162P3CN infection and disease progression

“…The promotion of combined antiretroviral therapy (cART) among HIV-1 infected people has resulted not only in a significant reduction of acquired immunodeficiency syndrome (AIDS)-associated mortality but also in the decrease of viral spread especially after the global efforts of treatment as prevention (Deeks et al, 2016;Brault et al, 2019). However, due to the unlikely life-long sustainable cost and compliance of cART, new approaches for preventing and curing HIV-1 remain urgently needed to fight the global HIV/AIDS pandemic (Deeks et al, 2016).…”