A year and a half gone, two HIV vaccine studies shut down. That’s the case with the Janssen Pharmaceutical Cos. of Johnson & 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.