HPV vaccination and cancer prevention: what to know

What HPV is and why it matters

Human papillomavirus, or HPV, is a group of very common viruses spread through skin-to-skin and sexual contact. Most sexually active people will catch some type of HPV during their lives, and usually the body clears it without any problem. However, some high-risk types can cause changes in cells that, over many years, may develop into cancer. HPV causes almost all cervical cancers and also contributes to some cancers of the anus, penis, vagina, vulva and the mouth and throat. Certain other types cause genital warts. Because the virus is so common and its cancers develop slowly and silently, preventing infection in the first place has an enormous impact on cancer rates.

How the vaccine prevents cancer

The HPV vaccine teaches the immune system to recognise and block the high-risk types of the virus most responsible for cancer, as well as the types that cause most genital warts. It does not contain live virus and cannot give you HPV or cancer. By preventing infection, it stops the cell changes that could otherwise progress to cancer over decades. The vaccine works best when given before someone is exposed to HPV, which is why it is offered to young people, ideally before they become sexually active. Real-world evidence is striking: in countries with high uptake, including the UK, rates of cervical pre-cancer and cancer in vaccinated groups have fallen sharply, showing the protection is real and lasting.

Who is offered the vaccine in the UK

In the UK, the HPV vaccine is offered routinely to all children in school, usually in Year 8, around ages 12 to 13, to both girls and boys. Vaccinating boys as well as girls protects them directly and reduces the spread of the virus overall. A single dose is now used for most young people, reflecting evidence that it gives strong protection. Those who miss the school programme can still catch up, generally up to age 25. The vaccine is also offered to certain groups at higher risk, including men who have sex with men up to a certain age and some people with weakened immune systems. If you are unsure whether you were vaccinated, your GP can advise.

Safety and side effects

The HPV vaccine has been given to hundreds of millions of people worldwide and has an excellent safety record, closely monitored by regulators including the UK's MHRA. Like any vaccine, it can cause mild, short-lived side effects: a sore arm at the injection site, redness or swelling, and sometimes a headache or feeling tired. These usually settle within a day or two. Serious reactions are very rare. Fainting can occur around the time of any injection, especially in teenagers, so people are asked to sit for a short while afterwards. Extensive research has repeatedly confirmed the vaccine's safety, and the protection it gives against cancer far outweighs the risk of minor, temporary side effects.

Why screening still matters

The vaccine is powerful, but it does not replace cervical screening. It protects against the HPV types responsible for most, but not all, cervical cancers, and many adults being screened today were not vaccinated as teenagers. Cervical screening, offered in the UK to women and people with a cervix from age 25, now tests the sample for high-risk HPV first, which is a highly sensitive way to find those at risk early. Attending screening when invited catches cell changes before they can become cancer, whether or not you have had the vaccine. Together, vaccination and screening form a two-layer defence, and the aim is to make cervical cancer a rare disease — a goal now genuinely within reach.