Human Papillomavirus (HPV)
HPV is the most common sexually transmitted infection (STI) in the United States. In 2018, there were about 43 million HPV infections in the US, many among people in their late teens and early 20s. HPV is transmitted through skin-to-skin contact, during vaginal, anal, or oral sex. Most people who become infected with HPV will not have any symptoms and will clear the infection on their own. Yet, when HPV infections persist, they might lead to abnormal Pap tests, genital warts, or cancer.
There are many different strains of HPV, which are classified into two main groups: "high risk" and "low risk". "High-risk" HPV can cause cancer of the cervix, vagina, vulva, penis, anus, and throat. "Low-risk" HPV can cause genital and anal warts.
The HPV vaccine offers protection against most HPV related cancers and anogenital warts. Routine HPV vaccination is recommended for all children at age 11 or 12, and can begin as early as age 9. Catch up vaccination is available until age 26. Some adults ages 27–45 may decide to get the HPV vaccine based on discussion with their clinician, if they were not vaccinated when they were younger.