Johnson & Johnson Halts HIV Vaccine Trial Due to Lack of Efficacy in Preventing Infection

Johnson & Johnson (JNJ.US) has halted a large experimental AIDS vaccine trial in the Americas and Europe, following the failure of a similar vaccine trial in Africa, dashing hopes in the fight against this global epidemic. Johnson & Johnson announced the results of an independent periodic data review of the Phase 3 Mosaico study of the HIV vaccine regimen under investigation. The study's independent Data and Safety Monitoring Board (DSMB) determined that the regimen was ineffective in preventing HIV infection among study participants compared to placebo. However, no safety issues were found with the vaccine regimen.

The clinical trial was halted early after an independent data and safety monitoring board found that Mosaico did not significantly reduce the risk of HIV infection, the company said in a statement on Wednesday. The study had been testing the vaccine on 3,900 people, using a harmless virus called adenovirus 26 to expose the immune system to HIV proteins.

The trial used a vaccine regimen similar to the Imbokodo version, which was stopped in Africa in 2021 as it also failed to meet efficacy standards. This represents the latest setback in efforts to develop an HIV vaccine since the virus was first identified in humans about 40 years ago. While treatable, HIV still infects approximately 1.5 million people annually, and around 650,000 people died from related diseases in 2021.

Mitchell Warren, executive director of AVAC, a global HIV prevention advocacy organization, said: "It's disappointing that this particular candidate vaccine did not work, but Mosaico was an important, well-designed, and well-conducted trial. This trial demonstrates that in the current environment, not only is it possible to design and conduct HIV vaccine trials, but it is also necessary to do so."