Katherine Gill

Session highlighted that HIV and STI rates remain unacceptably high. The speakers summarized the history of approaches to prevention of STIs and broadly neutralizing antibodies for the prevention of HIV; and looked to the future emphasizing choice, considering populations most at risk and framing interventions with a human rights-based approach

Jean Michel Molina from the University of Paris highlighted the dramatic increase in bacterial STI incidence in the era of effective HIV prevention and treatment. Three major studies have demonstrated the short-term benefits of Doxycycline PEP in MSM, including a strong reduction in chlamydia and syphilis with the intervention being well tolerated and having little impact on gonorrhoea. There are however long-term uncertainties including concern around selection and clonal dissemination of more resistant STIs and impact on the microbiome. He advocated for cautious implementation by identifying those most at risk, monitoring antimicrobial resistance and the microbiome and involving community stakeholders. Nyaradzo Mgodi from the University of Zimbabwe emphasised that no single product or approach would end the HIV epidemic and that broadly neutralising antibodies could provide the field with much-needed choice. The AMP studies showed proof of concept for antibody use in HIV prevention and future trials would require combinations of more potent antibodies with better coverage to improve overall prevention efficacy. Triple combination antibody efficacy trials are planned for 2024/2025. These trials should target those most at risk of HIV including pregnant women and adolescents and strong consideration should be given to manufacturing, licensing and delivery methods.

Novel ways to prevent HIV and STI infections are needed. Cautious introduction of doxycycline PEP has the potential to drastically reduce rates of syphilis and chlamydia in MSM most at risk of these infections. Studies in women have not demonstrated the same reduction and further research is needed to understand this. Combinations of optimized next generation bnAbs with wider breadth and higher potency have the potential to neutralize close to 100% of global HIV-1 strains and improve understanding of how an effective vaccine may work and may also provide prevention and treatment options for HIV and other infectious diseases.