University of California, Merced professor Patricia LiWang has designed what may be the most effective chemical inhibitor against human immunodeficiency virus infection, the university announced this week.

LiWang's discovery combines two existing drugs to work between several times and several hundred times more effectively than existing inhibitors, depending on the strain of HIV.

The new inhibitor blocks HIV from entering a cell at two different steps of viral entry, an approach among the forefront of new strategies to stop the virus. Other existing inhibitors look to stop HIV from replicating or from integrating in to the human genome, rather than preventing entry.

Like all HIV inhibitors, LiWang's creation faces the challenge of the frequently-mutating virus, which oftentimes rapidly adapts to resist new drugs.

“However, since this drug is a combination of two inhibitors, it would be nearly impossible for a virus to mutate so it wouldn't get hit with either one of these drugs," LiWang said.

The inhibitor uses a special protein produced by harmless bacteria, allowing for easy production. The inhibitor could be added to a vaginal cream to protect against the virus.

More testing and development is needed before the drug can be used, including testing for side effects. Clinical trials are years away.