HPV and vaccination

How common

Human papillomavirus is so common that most sexually active people acquire at least one type in their lifetime. Over 200 types exist; around 40 infect the genital area. Most infections clear without treatment within 1–2 years and cause nothing.

What it causes

Low-risk types (mainly 6 and 11) cause about 90 percent of anogenital warts. Warts are harmless, treatable and not linked to cancer.

High-risk types (mainly 16 and 18, plus 31, 33, 45, 52, 58) cause cancer where infection persists. HPV is responsible for:

• Virtually all cervical cancer
• Around 90 percent of anal cancer
• Around 70 percent of vaginal and vulval cancer
• Around 60–70 percent of oropharyngeal cancer, which has risen sharply in high-income countries and now exceeds cervical cancer incidence in men in some (Chaturvedi et al., 2011)
• Around 60 percent of penile cancer

Cancer develops over years to decades, and only in a small minority of persistent infections. Smoking, immunosuppression and HIV all increase persistence.

Transmission

Skin-to-skin genital contact. Penetration is not required, and condoms reduce but cannot eliminate transmission because they do not cover all exposed skin — Winer et al. (2006, NEJM) found consistent condom use reduced acquisition by about 70 percent. It transmits between people of any gender, including woman to woman.

Because most infections are silent and can persist latently for years, a new diagnosis says nothing about when or from whom it was acquired. This is worth stating plainly: HPV is not evidence of recent infidelity.

The vaccine

The nonavalent vaccine covers types 6, 11, 16, 18, 31, 33, 45, 52 and 58. It is prophylactic, not therapeutic — it prevents acquisition and does not treat existing infection, which is why it is given before sexual debut where possible.

The population evidence is now strong:

• Lei et al. (2020, NEJM) followed 1.7 million Swedish women and found substantially reduced invasive cervical cancer among the vaccinated, with the greatest reduction in those vaccinated before age 17.
• Falcaro et al. (2021, Lancet), studying the English programme, found an 87 percent reduction in cervical cancer in women offered vaccination at 12–13.
• Drolet et al. (2019, Lancet) meta-analysed 65 studies across 14 high-income countries and found 83 percent reductions in HPV 16/18 in girls aged 13–19 and 67 percent drops in anogenital warts.

Two doses under 15, three doses over 15 or with immunosuppression. Most countries now vaccinate all genders, which protects against anal, penile and oropharyngeal cancers and improves herd effects. Catch-up vaccination is licensed to 45 in many countries; benefit is lower with more prior exposure but is not zero.

Safety data now cover hundreds of millions of doses. The most common adverse events are injection site pain and fainting from the injection itself. No causal link has been established to chronic fatigue, POTS, premature ovarian insufficiency, or autoimmune disease in large-scale surveillance.

Screening

HPV primary screening — testing for high-risk HPV DNA rather than cytology first — is now standard in the UK, Australia, the Netherlands and a growing number of countries, and detects more pre-cancer with fewer tests. Cervical screening is needed for anyone with a cervix regardless of gender identity, vaccination status, sexual orientation or number of partners.

Anal cytology screening is offered in some settings to people living with HIV and other higher-risk groups; the ANCHOR trial (2022) demonstrated that treating anal high-grade lesions reduces anal cancer incidence, strengthening the case for screening.

There is no routine HPV test for men, and no test for oral HPV in routine use.

If you have warts or an abnormal result

Warts: treated with topical imiquimod or podophyllotoxin, cryotherapy, or excision. They often recur and eventually clear as immunity develops.

Abnormal screening: this means cell changes, not cancer. Colposcopy examines the cervix; most changes are monitored or treated with a simple outpatient procedure with excellent outcomes.

Sources

• Lei J et al. "HPV vaccination and the risk of invasive cervical cancer." NEJM, 2020.
• Falcaro M et al. "The effects of the national HPV vaccination programme in England on cervical cancer and CIN3 incidence." Lancet, 2021.
• Drolet M et al. "Population-level impact and herd effects following HPV vaccination programmes: updated systematic review and meta-analysis." Lancet, 2019.
• Winer RL et al. "Condom use and the risk of genital human papillomavirus infection in young women." NEJM, 2006.
• Chaturvedi AK et al. "Human papillomavirus and rising oropharyngeal cancer incidence in the United States." Journal of Clinical Oncology, 2011.
• Palefsky JM et al. "Treatment of anal high-grade squamous intraepithelial lesions to prevent anal cancer (ANCHOR)." NEJM, 2022.
• WHO. Human papillomavirus vaccines: WHO position paper, current edition.

Last reviewed: August 2026.