Mosaico HIV Vaccine Study Stopped Early for Non-Efficacy

January 18, 2023

Today, the Mosaico study, a large-scale HIV vaccine efficacy study also known as HVTN 706/HPX3002, was stopped early for non-efficacy. The study took place in several countries in North and South America and Europe to test the safety and efficacy of the adenovirus26-based vaccine regimen among 3,900 cis-gender men and transgender individuals who have sex with cis-gender men and/or transgender individuals. An independent data and safety monitoring board, at a scheduled review of the trial data, found the regimen to be safe, but that it did not meet the pre-defined criteria for efficacy and recommended that the study be stopped and trial participants informed.

The Mosaico study used a similar version of the vaccine regimen in its companion study, the Imbokodo trial, which was stopped in August 2021 as it also did not significantly reduce the overall risk of HIV acquisition among over 2,600 cis-gender women in five sub-Saharan African countries.

Read the Janssen Pharmaceutical Company press release.

Read the HVTN press release.

Read the AVAC press release.

● The HVTN and AVAC will host a global webinar on Wednesday, January 25 to reflect on this news and how it may impact HIV vaccine R&D and prevention globally. Stay tuned for registration details soon.

“The hard truth is the science of HIV vaccine development is extremely challenging,” AVAC said in its statement. “HIV remains a global threat, and a safe, efficacious and accessible HIV vaccine is still needed to provide a durable end to the pandemic. At the same time, we now have more proven HIV prevention options than ever before, but they are not reaching everyone who needs and wants them. Even as researchers continue the necessary work of accelerating HIV vaccine research, the broader HIV response must act as if we may never have a vaccine and prioritize the roll out of existing prevention options and research for additional ones. Ending this pandemic requires simultaneous action on multiple fronts of research, development and delivery.”

We hope you join us on January 25 with your questions and comments to discuss the ways forward.