Researchers conducting a study on 600 participants making use of Truvada, an HIV prevention pill, have just revealed some interesting results.

After over two and a half years, results have shown that no new HIV infections have been discovered. The work and results have been published in the Clinical Infectious Diseases just this week.

According to IFL Science, the Truvada pill - taken on daily basis - is known as an HIV pre-exposure prophylaxis (PrEP), which has been approved by the US Food and Drug Administration back in July 2012.

Truvada is the first approved drug that can reduce the risk of contracting the infection among uninfected individuals that engage in sexual activity with HIV positive partners.

According to the Centers for Disease Control and Prevention, the pill works this way:

""Pre-exposure prophylaxis, or PrEP, is a way for people who do not have HIV but who are at substantial risk of getting it to prevent HIV infection by taking a pill every day. The pill (brand name Truvada) contains two medicines (tenofovir and emtricitabine) that are used in combination with other medicines to treat HIV. When someone is exposed to HIV through sex or injection drug use, these medicines can work to keep the virus from establishing a permanent infection."

"When taken consistently, PrEP has been shown to reduce the risk of HIV infection in people who are at high risk by up to 92%. PrEP is much less effective if it is not taken consistently."

"PrEP is a powerful HIV prevention tool and can be combined with condoms and other prevention methods to provide even greater protection than when used alone. But people who use PrEP must commit to taking the drug every day and seeing their health care provider for follow-up every 3 months."

For this particular San Francisco study, a Kaiser Permanente team was able to observe 657 PrEP users spanning 32 months, majority of which were gay or bisexual men.

There were no new HIV infections found among the study participants, even with high rates of sexually transmitted infections with the individuals. "Risky behavior" like injection drug use and lowered rates of condom use were also reported from the study.

Although they contracted other sexually transmitted infections like chlamydia, gonorrhea, and syphilis, there were no new infections of HIV.