Highly Anticipated HIV Vaccine Fails in Large Trial

Lisa O'Mary

January 19, 2023

The only HIV vaccine nearing the completion of testing trials is not effective at preventing HIV, officials announced Wednesday. 

The vaccine had been in development since 2019 and was given to 3,900 study participants through October 2022, but data shows it does not protect against HIV compared to a placebo, according to developer Janssen Pharmaceutical.

Experts estimate the failure means there won't be another potential vaccine on the horizon for 3 to 5 years, The New York Times reported.

"It's obviously disappointing," Anthony Fauci, MD, former head of the National Institute of Allergy and Infectious Diseases, told MSNBC, noting that other areas of HIV treatment research are promising. "I don't think that people should give up on the field of the HIV vaccine."

No safety issues had been identified with the vaccine during the trial, which studied the experimental treatment in men who have sex with men or with transgender people.

There is no cure for HIV, but disease progression can be managed with existing treatments. HIV attacks the body's immune system and destroys white blood cells, increasing the risk of other infections. More than 1.5 million people worldwide were infected with HIV in 2021 and 38.4 million people are living with the virus, according to UNAIDS.


UNAIDS: "Global HIV & AIDS statistics — Fact sheet."

MSNBC: "Another major HIV vaccine trial fails."

New York Times: "The Only H.I.V. Vaccine in Advanced Trials Has Failed. What Now?"

Johnson & Johnson: "Janssen and Global Partners to Discontinue Phase 3 Mosaico HIV Vaccine Clinical Trial."


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