November 5, 2012
Research reported on PubMed.gov finds that the effectiveness of vaginal microbicides for preventing HIV infection depends on the method of administration, and different methods may be better for different drugs. Macaques prepared with the experimental non-nucleoside reverse transcriptase inhibitor (NNRTI) MIV-150 administered in a carageenan gel experienced more than 80% protection when challenged with the simian analogue to HIV. The closely related NNRTI MIV-160 was ineffective adminstered in gel but was highly effective when administered in a slow-release vaginal ring.
We wonder whether a vaginal ring that stays inserted for a week or a month might not be a better, less compliance-dependent means of protection for women who can't negotiate condom use with their partners.