In an open-label study of women in southern and eastern Africa, a vaginal ring that is inserted once a month and slowly releases an antiviral drug was estimated to reduce the risk of HIV by 39%, according to statistical modeling. In addition, the study found that participants appeared to use the ring more in the open-label study than in a previous clinical trial. These and other results of the HIV Open Label Extension (HOPE) study were presented today at the 10th IAS Conference on HIV Science (IAS 2019) in Mexico City.
source https://www.lifetechnology.com/blogs/life-technology-news-blog/most-women-use-vaginal-ring-for-hiv-prevention-in-open-label-study