The beleaguered effort to develop an HIV vaccine has yielded yet another failure in the final stage of testing a candidate. An efficacy trial of a complicated vaccine regimen, developed by a Johnson & Johnson subsidiary in cooperation with the U.S. National Institutes of Health, stopped early because an interim analysis showed it offered no protection, sponsors announced last week.
The placebo-controlled study, dubbed Mosaico, assessed whether a series of six different shots could prevent HIV infection. Four shots delivered adenoviruses carrying a “mosaic” of genes from different HIV subtypes, and the final two contained two versions of HIV’s surface protein.
The trial involved 3900 men in Europe, South America, and the United States who have sex with men and with transgender people.
A similar study in South African women that ended in 2021 also found the strategy offered no protection. No other experimental HIV vaccines are in or nearing efficacy trials.