The only HIV vaccine has failed in a late-stage trial, researchers announced Wednesd. Aealing a significant setback to efforts to control the global HIV epidemic and adding to a decade-long list of failed efforts.
Called Mosaico, the trial was the result of a public-private partnership involving. The US government and pharmaceutical giant Janssen. It has been rolled out in eight countries in Europe and the Americas, including the US, starting in 2019.
Researchers enrolled about 3,900 men who have sex with men and transgender people, who are considered to be at substantial risk of HIV.
Study leaders decided to halt the massive research effort after an independent data. And safety monitoring board reviewed the trial’s results and found. No evidence that the vaccine reduced participants’ rates of HIV acquisition.
“It’s obviously disappointing,” Dr. Anthony Fauci. Who as the longtime head of the National Institute of Allergy. And Infectious Diseases (NIAID) was an integral part of the trial, said of the vaccine failure. However, he said, “there are many other approaches. Early in the HIV-vaccine research pipeline that he sees as promising.
“I don’t think people should give up on the HIV vaccine,” Fauci said.
Fauci has previously said he doesn’t want to retire from NIAID until the HIV vaccine is proven. To be at least 50% effective — enough, in his view, to warrant a global rollout. Instead, leaving this dream unfulfilled, he retired from the post at the end of last month.
In addition to NIAID and Janssen, a division of Johnson & Johnson, the trial was led . By the HIV Vaccine Trials Network, headquartered at the Fred Hutchinson Research Center. In Seattle, and the US Army Medical Research and Development Command.
Mosaico’s lack of efficacy was not unexpected, experts said, given the recent failure. Announced in August 2021, of a separate clinical trial called Imbokodo, which tested. Wsimilar vaccine in women in Africa. Between the two trials, NIAID spent $56 million, according to an agency spokeswoman.
The vaccines tested in both trials used a common cold virus to deliver what’s known. As a mosaic immunogen, which includes genetic material. From different HIV strains circulating around the world. And is intended to trigger a strong and protective immune response, according. To the National Institutes of Health.
Mosaico includes an additional ingredient intended to extend resistance.
Participants in Mosaico, aged between 18 and 60, received four injections over 12 months. Either of the vaccine or a placebo. The monitoring board found. No significant difference in the rate of HIV acquisition between the two study groups.
Fauci said an important limitation of. The Mosaico vaccine was that it produced antibodies against HIV. As opposed to neutralizing ones — known as neutralization.
“It is becoming clear,” he said, “that vaccines that do not produce neutralizing antibodies are not effective against HIV.”
Up-and-coming HIV vaccine innovations could hold the key, including efforts that. Rely on the cutting-edge mRNA vaccine technology behind some coronavirus vaccines, Fauci said.
The critical problem that has bedeviled HIV vaccine research for decades, Fauci noted. Is a critical weakness that the virus is already successfully exploiting: the natural immune response. To infection is not sufficient to defeat the virus.
“So vaccines have to do better than natural transmission to be effective,” he said. “That would be a very high bar.”
In 1984, following the discovery of HIV as the cause of AIDS the previous year. President Ronald Reagan’s health secretary, Margaret Heckler. Famously claimed that a vaccine for the virus would be available within two years.
In the decades since, there have been nine late-stage clinical trials of HIV vaccines. be on a direct path to licensure if it proves effective. Only one of these vaccines showed efficacy in a trial conducted.
In Thailand between 2003 and 2006 – and only at a modest level.
In the years since, a phalanx of researchers worldwide has studied the Thai trial in hopes of developing. Insights for further HIV-vaccine development.
The year-long effort to design the Imbocodo and Mosaico vaccines was part of the effort. To build on the modest success of the Thai trial.
“We hoped we would see some signal of efficacy from this vaccine,” said Dr. Susan Buchbinder. An epidemiologist at the University of California, San Francisco, who co-led the Mosaico trial. He added that, promisingly, like the Imbokodo trial, there is no one about the safety of the vaccine