"std"

The proposal comes after studies found some people who took the antibiotic doxycycline within three days of unprotected sex were far less likely to get chlamydia, syphilis or gonorrhea compared with people who did not take the pills after sex.

The human papillomavirus (HPV), which is what causes it, is an infection. More than 15,000 viruses make up the HPV virus category.