Like you and the more than 6,000 colleagues who attended the 9th IAS Conference on HIV Science (IAS 2017) in Paris, we were in awe of the scientific data presented from Swaziland last July1. Sitting in the plenary hall, we learned that new HIV infections there were cut almost in half in only six years. That – in the country with the highest HIV prevalence in the world – is incredible.

And yet in the same room only a few days later, we learned of the explosive expansion of HIV in middle-income countries in Eastern Europe, where new infections have risen by 60% since 20102.

Despite global scientific advancements and increased sharing of “best practices”, there are clearly two entirely different narratives of HIV unfolding across the world. What is at the core of this divergence, and why does it persist?

One reason: politics.

In resource-limited countries where strong national commitment is combined with robust international support, the prospect of minimizing the epidemic to the point where it is no longer a serious public health threat appears increasingly feasible. Where political commitment on AIDS is strong, we have allowed science to guide our response.

However, in many other settings, ideology seems to be outweighing science in the HIV response (and in much of public health in general). Harmful political choices, including rapid donor transitions, criminalization and unscientific public health programmes, have led to predictably bad health outcomes, leaving many countries and regions with no end to AIDS in sight.

This year marks 30 years since the creation of the International AIDS Society (IAS), an important moment of reflection for our organization. We were founded in 1988 by a group of scientist-activists desperate to share information to stop the pandemic spreading around them. When the IAS was first created, there was no treatment for HIV and no prevention of mother-to-child transmission. There was pervasive stigma and discrimination, limited understanding of HIV transmission and disease progression, a lack of awareness of the degree to which HIV was predominantly spreading in sub-Saharan Africa, and by and large only condoms for prevention. To overcome massive challenges, those scientist-activists had to address the politics that stood in the way of achieving an effective response to the epidemic.

Since that time, astonishing scientific advances helped transform the fight against HIV, shifting the discourse on HIV from an urgent, activism-led discussion to a more technocratic, biomedical one – obscuring the political dimensions along the way. But in this moment of truth – when talk of “ending AIDS” is proving increasingly disconnected from reality for much of the world – we must face some uncomfortable questions:

Who are we ending AIDS for? Much of our current efforts appear specifically focused on heterosexual people in Southern and Eastern Africa. Yet within this region and throughout the world, millions are being left behind, particularly in key populations. How do we build an AIDS response that is both effective and equitable?

Why is prevention falling behind? We have an ever-growing list of effective prevention interventions but few resources to implement them. National programme planners have little room to accommodate prevention within their budgets and political leaders often lack the courage to tackle the questions that effective HIV prevention raises. How do we follow through from rhetoric to implementation of HIV prevention?

How should donor nations support the response to HIV in low- and middle-income countries outside of Southern and Eastern Africa? Repeatedly, we see countries transitioning from donor funding without the support to sustain the accomplishments of the past decade. Community systems wither and clinical care falters. What does responsible transition look like?