Intravaginal Ring Extremely Effective at Preventing HIV

A new device filled with an antiretroviral drug has demonstrated a 100% success rate protecting primates from the Simian immunodeficiency virus (SHIV), and will soon undergo its first test in humans.

Developed by researchers at Northwestern University (Chicago, IL, USA) and the University of Utah (Salt Lake City, USA), the tenofovir disoproxil fumarate intravaginal ring (TDF-IVR) device contains powdered tenofovir, an antiretroviral drug that is taken orally by 3.5 million HIV-infected people worldwide, that has not previously been studied topically. The ring is made of a unique elastomeric polymer construction that swells in the presence of fluid, delivering up to 1,000 times more of the drug than current intravaginal ring technologies.


The new ring is easily inserted and guards against HIV for one month, and because it is delivered at the site of transmission, it utilizes a smaller dose than pills. Other drugs, such as contraceptives or antiviral drugs to prevent other sexually transmitted infections, could also potentially be integrated into the ring, a feature that could increase user rates. The human clinical trial is slated for November 2013 at Albert Einstein College of Medicine (New York, NY, USA), and will evaluate the ring in 60 women over 14 days. The study describing the SHIV trial was published in the September 16, 2013, issue of the Proceedings of the National Academy of Sciences of the United States of America (PNAS).

“After 10 years of work, we have created an intravaginal ring that can prevent against multiple HIV exposures over an extended period of time, with consistent prevention levels throughout the menstrual cycle,” said lead author Associate Professor Patrick Kiser, MD, PhD, an expert in intravaginal drug delivery.

The proportion of women infected with HIV has been on the rise for a decade; in fact, in sub-Saharan Africa, women constitute 60% of people living with the disease. Antiviral drugs can prevent HIV infection, but existing methods for delivering the drug fall short, since drugs must be taken daily and require high doses, while vaginal gels must be applied prior to sexual intercourse. As a result, these methods prove ultimately ineffective, in light of the financial and cultural barriers rife in developing nations.

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