HPV (human papillomavirus) is the collective name for the DNA viruses of the family Papillomaviridae that infect human epithelial cells, with more than 200 genotypes. Rates of transmission through sexual contact are extremely high, and the great majority of sexually active adults are estimated to be infected at least once in life (Dunne et al., CDC, 2007). Most infections are asymptomatic and are cleared by the immune system, but persistent infection with certain high-risk types causes cervical and other cancers.

Types and disease classification

HPV types are divided by cancer association into high-risk and low-risk. High-risk (cancer-associated) types are led by HPV16 and 18, which account for about 70 per cent of cervical cancer; HPV31, 33, 45, 52, and 58 are also high-risk. Persistent high-risk infection of the cervix can progress through precancerous lesions (CIN, cervical intraepithelial neoplasia) to cervical cancer, usually over several to more than ten years. Beyond the cervix, high-risk types cause vaginal, vulvar, anal, penile, and oropharyngeal (throat) cancer. HPV-related oropharyngeal cancer has risen sharply in the West, with oral sex as the background route. Low-risk types are led by HPV6 and 11, which cause genital warts (condylomata acuminata); progression to cancer is rare, but recurrence is common and treatment may require several sessions. Over 90 per cent of genital warts are caused by HPV6 and 11.

Transmission and infection rates

HPV is transmitted mainly by skin and mucosal contact, with sexual activity (vaginal, anal, and oral) as the principal route. Condoms reduce transmission but do not fully prevent it, since skin contact outside the covered area can transmit the virus. Infection rates are very high: most people are infected within a few years of becoming sexually active. About 90 per cent of those infected clear the virus within two years through immune response; the problem arises when it persists.

Cervical cancer and HPV

Cervical cancer is the fourth most common cancer in women worldwide (WHO, 2020). Onset is common in the 20s to 40s, affecting women of reproductive age. Development follows a stepwise course: persistent HPV infection, precancerous lesions (CIN1–3), then invasive cancer. Because uterus-preserving treatment is possible at the precancerous stage, regular cervical screening (cytology, HPV testing) is critical.

HPV vaccine

The HPV vaccine prevents HPV infection, with high efficacy (over 90 per cent) when given before exposure. The vaccines in use include the 9-valent (covering HPV6, 11, 16, 18, 31, 33, 45, 52, 58), 4-valent, and 2-valent.

In Japan, routine vaccination began in 2013, but after reports of varied symptoms following vaccination, the proactive recommendation was suspended for about nine years (2013–2022). Vaccination rates fell to the low single digits during this period, drawing strong criticism that women who could have been protected were exposed to cervical-cancer risk. The proactive recommendation resumed in April 2022, and catch-up vaccination for those who missed the opportunity (born in fiscal 1997–2006) ran through March 2025.

HPV vaccination for males is increasingly recommended to prevent anal, penile, and oropharyngeal cancer and to reduce transmission to female partners. More than 59 countries (including the United States, Australia, and the United Kingdom) include males in routine programmes; in Japan, routine male vaccination remained unimplemented as of 2026 and is provided privately, with deliberation on routine inclusion proceeding in the Ministry of Health, Labour and Welfare.

Related terms

• Vagina
• Penis
• Clitoris
• Anus