An estimated two-thirds of American adults have human papillomavirus (HPV) , although only about a quarter of them carry a high-risk strain that can cause cancer, HealthDay reports. Researchers at New York University Langone Medical Center analyzed tissue samples from the skin, mouth, vagina and gut of 103 men and women that were stored in a U.S. National Institutes of Health database. The study was presented at the annual meeting of the American Society for Microbiology in Boston.

Sixty-nine percent of the individuals had one or more strains of HPV. Just a quarter of them carried one of the two HPV strains, types 16 and 18, that are known to cause most cases of cervical cancer, as well as some throat cancers and genital warts. The vaccine against HPV, Gardasil, prevents types 16 and 18 as well as 6 and 11.

The researchers theorized that certain strains of HPV—there are 148 known kinds, and 109 were detected in this study—may actually have the ability to keep others in check and to prevent their spread. The researchers compare HPV to the hot-button notion of the microbiome, in which bacteria thrives in the body in a healthy way, aiding normal functioning.

To read the HealthDay story, click here.