The participants of the International AIDS Society (IAS) Conference on HIV Science session on an HIV vaccine were welcomed by Lucy Stackpool-Moore, Director, HIV Programmes and Advocacy at the International AIDS Society, after which Susan Buchbinder, from the University of California, San Francisco, and the San Francisco Department of Public Health, made introductory remarks. Two recorded presentations were then shown, by Kevin De Cock and Gabriela Gomez, speaking, respectively, on the need for and role of an HIV vaccine and on modelling science around the requirements and impact of a putative vaccine.
UNAIDS’ Science Adviser, Peter Godfrey-Faussett, then moderated a lively panel discussion that included Yazdan Yazdanpanah, Kundai Chinyenze, Rachel Baggaley, Daisy Ouya, Jerome Singh and Paul Stoffels.
The first question was on whether a vaccine for HIV, if it arrived, would be too late in view of the other HIV prevention modalities available. The consensus was that a vaccine is still needed, especially in low- and middle-income countries and for key populations. The participants then discussed how good a vaccine would need to be. Relevant issues include efficacy and durability, but a priority is proof of concept of activity. The participants acknowledged that initial inconvenient dosing schedules are justified if it can be shown that a product is protective. Minimum efficacy probably needs to be in the region of 50-60% for products to be taken forward.
The discussion also covered engagement by big pharma-Johnson & Johnson is currently the major company pursuing HIV vaccine research, in conjunction with diverse governmental, nongovernmental and clinical partners. It was emphasized that people and individual motivations drive the science, both for HIV prevention and treatment.
Inevitably, the comparison of vaccine development for COVID-19 and HIV came up. The panellists emphasized, however, that the reasons for a lack of success so far in HIV was largely related to the complex nature of HIV itself.
The discussion ended on a note of realistic optimism, with acknowledgment of the benefits of scientific investment in HIV vaccine research to date, including for COVID-19, but with recognition that long-term commitment is still required. The results of the two ongoing phase three trials (Imbokodo and Mosaico) are eagerly awaited.