In the majority of cases, HIV is transmitted through sexual intercourse -- nothing new there.
What is new is that Gladstone researcher Nadia Roan has found that a synthetic molecule called Surfen may help block the spread of HIV.
"You can greatly decrease the likelihood that HIV gets transmitted from person to person during sexual contact," she said.
Here's how it could work: SEVI is a protein found in semen and for some reason SEVI helps HIV attach itself to our immune cells.
In other words SEVI facilitates the spread of the deadly virus. But, When Surfen is introduced, it interferes with that process.
"Some experiments we carried out suggest that it can actually stick to the SEVI and when it's stuck to the SEVI the SEVI can no longer stick very well to the HIV," Roan said.
This new finding could lead to the development of yet another way for people to protect themselves against HIV.
Dr. Warner Greene is the director of the Gladstone Institute of Virology and Immunology. He believes Surfen could eventually be put into microbicides.
A microbicide is a gel or cream which reduces a person's risk of HIV infection.
"So just like we treat HIV infected patients with multiple combination of drugs, we envision microbicides also having combinations of agents targeting different parts of the virus and the host factors that propel viral infection," he said.
Charles Fann is with Tenderloin Health, which serves people with HIV.
"It would actually empower some people who don't have sexual choices to have another level of control or power," he said.
HIV has infected 60 million people worldwide, killing 25 million of them since it was discovered in 1981.