Many women will be infected with the HPV virus at some time during their lifetime. Often the virus causes no harm and goes away without treatment.
- Genital warts
- Changes in the cervix, which may develop into a cancer
- Changes in the vaginal tissues, which may develop into vaginal cancer
Of the different types of HPV, types 16 and 18 cause about 7 out of 10 (70%) cancers of the cervix. Most of the remaining 30% of cervical cancers are associated with other high risk HPV types. HPV types 6 and 11 cause genital warts but are less likely to cause cancer.
You can find out more about the risks and causes of cervical cancer in the cervical cancer section of CancerHelp UK. HPV is also a risk factor for other types of cancer including vaginal cancer, vulval cancer, anal cancer and cancer of the penis.
Research into vaccines to prevent HPV
Several research trials have tested vaccines as a way of preventing infection with HPV. A trial testing Gardasil called FUTURE II reported its results in October 2005. This phase 3 trial involved over 12,000 women aged between 16 and 26. These women did not have HPV before the start of the trial. The women were divided into two groups. Half the women were given Gardasil and the other half had a dummy vaccine (placebo). Both groups of women had 3 injections of either the vaccine or placebo over six months. Over the following two years the women had regular checks to see if they had got HPV, or had any precancerous changes to the cells of the cervix, which could develop into a cancer. The group who had the vaccine showed no precancerous changes. Of the 5,258 women who had the placebo, 21 had precancerous changes, which is 0.4%. The researchers found that Gardasil protected against HPV types 6 and 11, as well as 16 and 18.
Two other phase 3 trials have tested the vaccine Cervarix. The first was for women under 26 and closed in July 2005. It involved over 18,000 women from all over the world, including the UK. This study was called ‘PATRICIA’ (PApilloma TRIal to prevent Cervical cancer In young Adults). The second was for women of 26 and over, and closed in August 2006. On the basis of results from these trials, the European Commission has approved Cervarix for the prevention of precancerous changes in the cervix in girls and women between the age of 10 and 25.
The HPV vaccination programme
In the UK, girls in year 8 at school (aged 12 to 13) are offered the HPV vaccine. The vaccine the Government has chosen to use is Cervarix. Girls have three injections over 6 months given by a nurse. A letter about the vaccine and a consent form is sent to the parents of the girl before she has the vaccine. It is up to her whether she has the vaccine. A 2 year 'catch up' programme also started in Autumn 2008, to vaccinate girls aged between 13 and 18. The NHS immunisation website has more information about the vaccination programme and when girls in the catch up programme will be offered the vaccine.
It is also possible to have the vaccination privately. The cost for private treatment varies from doctor to doctor. We are hearing reports of about £500 being charged for a course of 3 injections.
This research means that if girls take up the vaccination the programme will prevent at least 7 out of 10 cancers of the cervix and possibly even more in the future. But it takes between 10 and 20 years for a cancer to develop after HPV infection. So any benefits in reducing cervical cancer won’t be seen for quite a long time. But the number of cases of pre-cancerous changes in the cervix (CIN) will fall quite rapidly.
It is not certain how long the vaccination gives protection for. So far the trials have followed people up for 6 years so we know that it lasts at least this long. More research is needed to find out how long it lasts and if women need a booster dose at some time.
Side effects of the vaccine
The side effects are usually mild and include
- Aching muscles
- Redness and soreness around the site of the injection
- Feeling and being sick
- Stomach pain
- Itching, rash
Do we still need cervical cancer screening?
We'll still need the cervical screening programme in the UK, even after the vaccines become widely available. The vaccines don't prevent infection with all types of HPV. Also from the research so far, we don't think the vaccines will help prevent cervical cancer in women already infected with HPV. And it takes about 10 to 20 years after HPV infection for a cervical cancer to develop.
So it’s very important to remember that women will still need cervical cancer screening (smear tests) for many years to come. There is more information about cervical cancer screening in the cervical cancer section of CancerHelp UK.
A UK trial is planned to look at a vaccine to treat women already infected with HPV. You can find out more about the latest research into cervical cancer in the cervical cancer section of CancerHelp UK.