HPV and cervical cancer: how vaccination and screening protect you

Cervical cancer is one of the few cancers whose cause is precisely known. In almost all cases it is caused by the human papillomavirus (HPV). That means there are two ways to protect yourself: a vaccine that prevents infection, and regular testing that finds changes long before cancer develops.

What HPV is and why it is dangerous

HPV is a very common virus spread through sexual contact. Most people get it at least once in their lives, usually without any symptoms. In 9 cases out of 10 the body clears the virus by itself within 1–2 years.

The danger is that some types — above all 16 and 18 — sometimes stay in the cells for a long time. Over 10–20 years they gradually change the cells of the cervix, and cancer can eventually develop. The same types also cause some cancers of the anus, throat, penis and vulva — so HPV is not only a women’s issue.

Vaccination: who and when

The HPV vaccine protects against the types that cause most cancers. It works best when given before a person becomes sexually active, before any contact with the virus.

• Age 9–14 — the best age for girls and boys. 1–2 doses are needed.
• Age 15–26 — vaccination is also recommended, usually 2–3 doses.
• After 26 — the benefit is smaller, but it is sometimes still given. The decision is made with a doctor.

The vaccine does not treat a virus already in the body. But it protects against other dangerous types, so it makes sense even after infection with one of them.

The vaccine has been studied in millions of people. Common side effects are pain and redness at the injection site, sometimes a headache or tiredness on the first day. In countries that vaccinate all teenagers, cervical cancer among young women has fallen sharply.

HPV test and smear

The vaccine does not cover every type, so vaccinated women still need screening. The usual recommendation is:

• from 25 to 65 — an HPV test every 5 years;
• or a cervical smear (Pap test) every 3 years if an HPV test is not available.

Both samples are taken during a routine gynaecological examination — it is quick and almost painless.

What to do if HPV is found

A positive HPV test is not a cancer diagnosis. It means the virus is present and you need follow-up. Usually the doctor will:

• arrange a smear or colposcopy — an examination of the cervix under magnification;
• if there are no changes, repeat the test in a year: by then the virus has often cleared by itself;
• if pre-cancerous changes are found, remove the affected area — a small procedure after which women can still have children.

There are no tablets or injections that “kill” HPV. Quitting smoking helps the body clear the virus: in smokers HPV lasts longer and leads to cancer more often.

In short

• Vaccinate children aged 9–14 — both girls and boys.
• Women from 25 — an HPV test every 5 years, even after vaccination.
• A positive test is a reason for follow-up, not for panic.

This article is for information only. Talk to your doctor about vaccination and screening.