A year and a half gone, two HIV vaccine studies shut down. That’s the case with the Janssen Pharmaceutical Cos. of Johnson and Johnson as the phase III Mosaico study of its HIV vaccine regimen was not effective in preventing infection compared to placebo. Based on a data and safety monitoring board’s report saying the study was not expected to hit its primary endpoint, Janssen discontinued the clinical trial more than a year ahead of its estimated March 2024 completion date.