The HPV vaccine: what it is, who it is for and when it is given

Published: 24 June 2026 · Medically reviewed by: Op. Dr. Murat Alpay

What the HPV vaccine protects against, the ideal age, the catch-up window up to 45, and how many doses are needed depending on the age at which the course starts.

Human papillomavirus (HPV) is very common and can set the stage for changes in the cells. Thanks to developments in medicine, it is now possible to protect against this virus and the diseases it causes before exposure occurs. Below are the questions asked most often about the vaccine.

What the vaccine is, and why it matters

The HPV vaccine is a prophylactic — preventive — vaccine developed to protect the body against human papillomavirus. Its central value is that it prevents the virus types capable of causing cancer and warts from establishing an infection. Given to someone who has not yet encountered the virus, it offers protection of over 95%.

One point must be clear: the HPV vaccine is not a treatment. It does not speed the clearance of an infection already present, and it does not treat an existing lesion (a change in the tissue). It prevents new infections.

What it protects against

Some HPV types are low-risk and cause warts; others are high-risk and can begin the process that leads to cancer. The nine-valent vaccine in common use today creates a shield against the nine types responsible for most disease (types 6, 11, 16, 18, 31, 33, 45, 52 and 58). It protects mainly against:

• cervical cancer
• cancers of the vagina and vulva
• anal cancers
• genital warts (condyloma)

At what ages it is given

The ideal window is 9-12 years of age, before someone is sexually active and therefore before exposure. If it was not given then, all guidelines recommend it as a catch-up vaccination up to the age of 26. Beyond that, the US Food and Drug Administration and current scientific guidance have extended approval to the age of 45. Adults between 27 and 45 can therefore be vaccinated safely after discussing their own risk and expectations with their doctor.

How many doses

The schedule depends on the age at which the course begins:

• Starting before 15: the immune system responds strongly enough at this age that 2 doses are sufficient. The second dose is given 6 to 12 months after the first.
• Starting at 15 or over: 3 doses are needed for full protection, at months 0, 1-2 and 6. That is, the second dose one or two months after the first, and the third exactly six months after the first. A three-dose schedule is also used for people whose immune system is suppressed, whatever their age.

The HPV vaccine is one of the strongest and safest measures available against certain cancers, and among those with the most evidence behind them. Even so, being vaccinated does not replace cervical screening: continue with smear and HPV testing at the intervals your doctor recommends.