This question will resolve to YES if the vaccine trial is found to have >= 90% efficacy in preventing new HIV transmission in participants.

Context per NIH:

HVTN 142 is taking place at six sites in the United States and four in South Africa and will enroll 95 HIV-negative participants. Participants will be randomly assigned to one of four study arms: three arms will each receive a different dose of the vaccine, and one will receive a placebo. To optimize participant safety, this study will only enroll people already living with asymptomatic CMV. Initial results are expected in late 2024, and an optional long-term sub-study will continue to follow volunteers for up to three years after their first vaccine dose.

https://www.nih.gov/news-events/news-releases/clinical-trial-hiv-vaccine-begins-united-states-south-africa