HIV can penetrate normal, healthy vaginal tissue and infect women, according to researchers at the Northwestern University Feinberg School of Medicine in Chicago, The Washington Post reports.

According to the article, it was once believed that the HIV virus was too large to penetrate the normal lining of the vaginal tract. But researchers have found that the virus can travel through healthy genital tissue and infect immune cells.

“We urgently need new prevention strategies or therapeutics to block the entry of HIV through a woman’s genital skin,” said Thomas Hope, the principal investigator in the study and a professor of cell and molecular biology.

If confirmed by future studies, the findings can help the development of new microbicides and vaccines to protect women from the virus. Women account for 26 percent of all new HIV cases in the United States and more than half of new HIV infections worldwide.