Though an HIV cure may not be possible for many years, a new vaginal cream may act as a new tool for prevention.

Researchers led by Humberto Lara Villegas of the University of Monterray, in collaboration with a research team at the University of Texas, found that silver nanoparticles were able to stop the transmission of the human immunodeficiency virus (HIV). They have further developed the research to create a vaginal cream that can block the virus and prevent HIV infection.

The silver nanoparticles that are involved in the vaginal cream are able to attach themselves to a particular protein known as GP120, which aids in the process of HIV infecting human immune cells. The nanoparticles block the GP120 protein, thus protecting immune cells from HIV infection.

“Normally, the medication used against the virus act within the cell to avoid its replication,” Lara Villegas told Medical News Today. “This is a very different case, given that the nanoparticle goes directly against the HIV and no longer allows its entry to the cell.” Villegas and his team tested the cream in the lab, using human tissue samples of cervical mucous membrane — and the lab tests were successful. The cream works in less than one minute after it is applied, and is able to defend the body from virus transmission up to several days. There is still a chance that the cream may cause complications or adverse side effects, so the researchers will continue testing to ensure it’s safe to apply.

Researchers have in the past developed other forms of prevention for HIV, such as the dual-intravaginal ring (IVR), which can protect women from both HIV infection and unwanted pregnancy. The vaginal ring was developed because researchers noticed that most of the world’s unplanned pregnancies — as well as highest rates of HIV — occurred in areas in South America and sub-Sahara Africa, and the ring could be a way to help curb these numbers. The IVR is considered a multipurpose prevention technology (MPT), which is a new form of reproductive health technology that has the ability to be useful in third-world countries.

The most common way to prevent HIV is to wear a condom during sexual intercourse, or to abstain from sex completely. HIV can be spread through semen, vaginal fluid, blood, or breast milk of an infected person. Having unprotected sex is a sure-fire way to contract HIV; sharing drug needles or syringes is another easy way.

According to the National Institutes of Health (NIH), there are in fact medications out there that are used to prevent HIV — for those who are at a high risk of transmission from sex with an infected person. They include pre-exposure prophylaxis, which involves taking a medicine every day. Post-exposure prophylaxis, meanwhile, is used after a person has been exposed to HIV — taking this medicine can help reduce the risk of actual infection. Pregnant women who are infected with HIV are also typically given plenty of drugs to reduce the risk of transmission to the infant.

As for Villegas and his team, now that the lab tests done on human tissue samples have been positive, they will next test the cream on mice that are modified with human immune cells. Finally, they will test the cream in human clinical trials. The researchers hope that the cream may also work against other sexually-transmitted infections (STI’s) such as the human papilloma virus (HPV). The silver nanoparticles would block the infection in a similar way it does for HIV.

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