Cervical cancer vaccine
Dr Harriet Doyle explains the importance of an HPV vaccine for girls aged 11 to 14.
Cervical cancer is the fourth most common cancer globally. It mainly affects sexually active women between the ages of 30 and 45 years. Since the cervical screening programme was introduced in the UK, the incidence of cervical cancer has fallen by 44% and the number of deaths from the disease by 70%. However there are still over 3,000 new cases diagnosed each year.
99% of all cases of cervical cancer are caused by the human papillooma virus (HPV). HPV is a very common virus that can be passed on through any type of sexual contact with a man or a woman. There are more than 100 different types of HPV, many of which are harmless. However some types can cause abnormal changes to the cervix, which may eventually lead to cervical cancer. Two types of HPV (HPV 16 and HPV 18) are known to be responsible for 70% of all cases of cervical cancer. These types of HPV infection don’t have any symptoms so many women don’t realise they have the infection. Additionally they are also responsible for 85% of anal cancer, 40-60% of vaginal and vulval cancers and some throat and tonsillar cancers.
The good news is that there is now an effective vaccine against HPV 16 and 18 - a great step forward in cancer prevention!
In 2008 a vaccination programme was introduced in the UK, which protects against HPV 16 and 18 and is offered in all schools to girls between the ages of 11 and 14. It is important that the vaccine, known as Gardasil, is given before the girls are sexually active as they will not gain any protection from it if they already have HPV infection. A letter about the vaccine and a consent form is sent to the parents prior to the girl being given Gardasil, and it is up to them, and her, as to whether she proceeds with the programme. If they decide to go ahead she will receive two injections, between 6 and 24 months apart.
Any benefits in reducing cervical cancer won’t be fully apparent for quite a long time. This is because it takes up to 20 years for a cancer to develop after HPV infection. However studies in Australia, which introduced the vaccine two years before the UK are very promising, with Gardasil showing 99% efficacy in preventing cervical cancer in women with no pre-existing HPV 16 or 18 infection. The next question is whether we should be offering the same vaccine to boys to protect them from contracting risky HPV.
Dr Harriet Doyle
Tavyside Health Centre