The ring is easily inserted and stays in place for 30 days,delivering a measured amount of the anti-retroviral tenofovir directly to the site of transmission.

Northwestern University visiting associate professor Patrick Kiser has developed the new ring with support from the National Institute of Allergy and Infectious Diseases and this ring showed a 100% success rate in protecting primates from the simian immunodeficiency virus.

In the near future, the long lasting device will be tested the in humans for the first time.

Kiser said: "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."

The ring’s elastomer swells in the presence of fluid and delivers about 1,000 times more of the drug than current intravaginal ring technology, such as NuvaRing, which are made of silicon and have release rates that decline over time.

Clinical trial will be conducted on 60 women over 14 days in November 2013 at Albert Einstein College of Medicine in New York to assess the ring’s safety and measure how much of the drug is released and the properties of the ring after use.

Kiser noted that other drugs such as contraceptives or antiviral drugs could potentially be integrated into the ring to prevent other sexually transmitted infections — a feature that could increase user rates.