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PrEPVacc Investigators

IAS statement: IAS calls for stepping up HIV vaccine R&D after PrEPVacc halts its vaccine arm

Photo: PrEPVacc Investigators

6 December 2023 (Geneva, Switzerland) – PrEPVacc announced today that it "has stopped further vaccinations as there is little or no chance of the trial demonstrating vaccine efficacy in preventing HIV acquisition". Its pre-exposure prophylaxis (PrEP) trial is set to continue.

While IAS – the International AIDS Society – is disappointed at this outcome, we believe that this provides us with lessons to drive HIV vaccine research and development (R&D) with urgency.

“We cannot and will not lose hope that the world will have an effective HIV vaccine that is accessible by all who need it, anywhere,” IAS Executive Director Birgit Poniatowski said. “A vaccine remains one of our most powerful tools to reach and change the lives of vulnerable communities and key populations in the most affected parts of the world.” 

PrEPVacc, an African-led, European-supported HIV prevention study, has been running in four sites in Uganda, Tanzania and South Africa since 2018. With 1,513 participants (men and women aged 18-40 years), it has been testing two experimental vaccine combination regimens to protect against acquiring HIV and a new form of PrEP. 

The PrEPVacc sites are in eastern and southern Africa, the region most heavily impacted by HIV. It is home to almost 21 million of the 39 million people living with HIV globally: 500,000 people in the region acquired HIV in 2022, and 61% of them were women and girls.

HIV prevention is often approached through a combination of methods, including condoms, antiretroviral therapy (ART) and behavioural interventions. A successful HIV vaccine could provide long-term protection with a single or limited number of doses, simplifying adherence and reducing the need for ongoing interventions. 

A vaccine could help reduce the stigma associated with HIV by normalizing prevention practices. Importantly, it could ease the burden on key populations, including gay men and other men who have sex with men criminalized by some of the world’s harshest anti-gay laws in parts of the PrEPVacc study region. 

An HIV vaccine could alleviate healthcare costs and contribute to the economic well-being of communities in affected regions. Also, the pursuit of an HIV vaccine drives scientific innovation and contributes to our understanding of the immune system and infectious diseases: a case in point is the rapid development of vaccines for COVID-19, which drew heavily from HIV vaccine research. 

At the IAS, we believe that even when efficacy studies have not shown the desired outcomes, they offer valuable lessons and data that researchers can use to refine their approaches. Understanding why certain strategies are unsuccessful is crucial for making informed adjustments and moving us closer to an effective vaccine. 

The IAS is committed to ending HIV as a threat to public health and individual well-being, and we call on all stakeholders, including in Europe, to step up HIV vaccine R&D to make that a reality.

The IAS promotes the use of non-stigmatizing, people-first language. The translations are all automated in the interest of making our content as widely accessible as possible. Regretfully, they may not always adhere to the people-first language of the original version.