By: Alanna Shaikh, MPH on June 17, 2010 A new microbicide study has begun in South Africa, testing a vaginal ring that releases microbicides to protect women from HIV infection. The ring is replaced once a month and requires no special effort on the part of the user or her partner. I heard Zeda Rosenberg, head of the International Partnership for Microbicides, talk about this ring at the Women Deliver conference. This is the 15th product tested by the partnership, and it’s the one that Dr. Rosenberg thinks is most likely to succeed. If the microbicidal ring trial is successful, this will be a big deal. A once-a-month ring would allow women to protect themselves without requiring the cooperation of their partner. It would be easy to provide and easy for women to use. I hope Dr. Rosenberg is right about the ring. We won’t know until the study completes in 2015, and there have been plenty of microbicide failures to date. So far, they have all been useless against. Except, of course, for Nonoxynol-9, which actually increased the risk of infection.