Human papillomavirus (HPV) is a double-stranded DNA virus and a source of infection that primarily affects the skin and mucous membranes. It can be transmitted through sexual contact and contaminated surfaces. There are over 200 genotypes of HPV, approximately 40 of which infect the anogenital region. High-risk HPV types, such as HPV-16 and HPV-18, can lead to the development of various cancers, particularly cervical cancer. Factors that increase the risk of transmission include having multiple sexual partners, early initiation of sexual activity, and having an uncircumcised male partner. Low socioeconomic status, poor nutrition, immunosuppression, and co-infections with HIV, genital herpes, or chlamydia can result in persistent and severe HPV infection.
Three types of vaccines have been developed against HPV: bivalent, quadrivalent, and nonavalent vaccines. The bivalent vaccine provides protection against HPV-16 and HPV-18; the quadrivalent vaccine is effective against HPV-16, HPV-18, as well as HPV-6 and HPV-11. The nonavalent vaccine offers the broadest protection, covering nine different types of HPV. All vaccines are approved for males and females aged 9 and older. Vaccination before the onset of sexual activity significantly increases protection against cervical cancer.