Everything you need to know about the cervical cancer (HPV) vaccine.
Since September 2008 there has been a national programme to vaccinate girls aged 12-13 against human papilloma virus (HPV).
There is also a three-year catch up campaign that will offer the HPV vaccine to 13-18 year old girls.
The programme is delivered largely through secondary schools, and consists of three injections that are given over a six-month period.
Human papilloma virus (HPV)
Human papilloma virus (HPV) is the name of a family of viruses that affect the skin and the moist membranes that line your body, such as those in your cervix, anus, mouth and throat. These membranes are called the mucosa.
There are more than 100 different types of HPV viruses, with about 40 types affecting the genital area. These are classed as high risk and low risk.
What HPV infection can do
Infection with some types of HPV can cause abnormal tissue growth and other changes to cells, which can lead to cervical cancer. Infection with other forms of HPV can also cause genital warts.
Other types of HPV infection can cause minor problems, such as common skin warts and verrucas.
Around 30 types of HPV are transmitted through sexual contact, including those that can cause cervical cancer and genital warts. Genital warts are the most common sexually transmitted infection (STI) in the UK.
HPV infection is also linked to vaginal cancer and vulval cancer, although both are rare conditions.
In the UK, cervical cancer is the twelfth most common women’s cancer. Worldwide, it is the second most common. In the UK, a woman’s lifetime risk of developing cervical cancer is about one in 116 (0.86%).
Cancer of the cervix usually takes 10-20 years to develop. In the UK, more than 1,000 women die from cervical cancer each year.
Cervical screening picks up abnormalities in about 200,000 women a year, and around 2,800 women a year are diagnosed with cervical cancer.
Regular cervical screening is the best way to identify abnormal changes in the cells of the cervix. Following the introduction of the national HPV vaccination programme, the NHS cervical screening programme will continue to play an important part in checking women who are between 25-65 years of age for early-stage cell changes.
Why HPV vaccination is necessary
Clinical trials of the vaccine used in the UK human papilloma virus (HPV) vaccination programme (Cervarix) have shown that in adult women, between 15-25 years of age, it protects against HPV types -16 and -18 which together cause about 70% of cases of invasive cervical cancer.
However, the vaccine does not protect against all types of HPV, and is therefore not guaranteed to prevent cervical cancer. This is why regular cervical screening continues to play an important role in detecting potentially cancerous cell changes in the cervix.
The trials also showed that the vaccine protects against these two types of HPV in children who are between 10-14 years of age. The Joint Committee for Vaccination and Immunisation (JCVI) discussed vaccinating boys as well as girls, but decided that it would not be cost effective in preventing cervical cancer.
To provide the most benefit and protection, the HPV vaccine needs to be given before sexual activity begins.
What HPV vaccines do not do
Cervarix does not:
- protect against genital warts (although another licensed HPV vaccine, called Gardasil, does),
- create immunity against cervical cancer itself,
treat existing cervical cancer,
- treat HPV infection that is already present,
- protect against illnesses, or conditions, including cancers, that are not caused by infection with HPV types -16 or -18, or
- protect against infection with other types of HPV (you should therefore practise safe sex using condoms, which offer some protection against HPV infection).
High risk types of HPV
The most common high risk types of HPV, HPV-16 and HPV-18, cause over 70% of squamous cell cancers, which are the most common type of cervical cancer. Squamous cell cancer develops from the flat cells that cover the outer surface of the cervix, at the top of the vagina.
If your immune system does not deal with a high risk HPV infection, it can lead to cell changes (dyskaryosis) and abnormal growth of precancerous cells in your cervix. This is also known as cervical intraepithelial neoplasia (CIN). Although CIN is not cancer, if left untreated, it can develop into cancer in some women. It usually takes 10-20 years to develop.
HPV-18 is also thought to cause around 50% of all adenocarcinomas, which is the other main type of cervical cancer. Adenocarcinoma develops from the glandular cells which line the cervical canal (endocervix).
Approximately 95% of cervical cancers are squamous cell, and the remaining 5% are adenocarcinomas.
Low risk types of HPV
Low risk types of HPV include HPV-6 and HPV-11, which cause around 90% of cases of genital warts. The low risk types of HPV are unlikely to lead to cervical cancer because genital warts themselves do not cause cervical cancer.
HPV infection is transmitted through skin-to-skin contact. Genital HPV infection is common and is transmitted through sexual contact. The viruses that cause it can be present all over the area around your genitals and your anus.
You can be infected with more than one type of HPV. Most women have HPV infection at some time during their lives without it causing harm. Your immune system usually gets rid of it.
Having sex just once could expose you to the risk of genital HPV infection. Therefore, if you are infected with HPV, it does not necessarily mean that you have had a large number of sexual partners.
All sexually active women are at risk of having an HPV infection. Having a large number of sexual partners will increase your risk of becoming infected, as will starting to have sex at a young age.
Practising safe sex, using a method of contraception, such as condoms, can help you to prevent getting a genital HPV infection. However, condoms do not cover the entire genital area, and they are usually put on after sexual contact has begun.
Therefore, HPV infection can still be passed on even if you use a condom. It is still important for you to remember that as well as providing some protection against HPV, condoms are the most effective method of protection against other sexually transmitted infections (STIs).
In 99% of cases, cervical cancer results from a history of infection with high risk types of HPV.
If you are infected with a high risk type of HPV, you will have no symptoms.
HPV vaccination programme
HPV vaccination is part of the national immunisation programme and is given to girls between 12-13 years of age and is given in secondary schools. There is also a three-year catch up programme for girls between 13 and 18.
By the end of the catch up programme, all girls under 18 years of age will have been offered the HPV vaccine. At present, women who are 18 years of age or over are not routinely offered a vaccination against HPV. However, in the future, the Department of Health may decide to make the HPV vaccination available to women who are between 18-25 years of age.
Before deciding to be vaccinated, you should tell your GP if the person to be vaccinated has:
- a condition that makes them bleed more than normal, such as thrombocytopaenia, or
- a weakened immune system - for example, as the result of a genetic defect, or HIV.
As with any medicine, or vaccine, the HPV vaccine should not be used if your child:
- is allergic to any of its ingredients,
- has had an allergic reaction to a previous dose of the vaccine, or
- is suffering from an illness with a high fever.
However, there is no reason to delay vaccination if your child has a mild fever, or an infection, such as the common cold.
How the HPV vaccine is given
Before your child has the human papilloma virus (HPV) vaccination, you will receive information about the vaccination schedule and a consent form.
The vaccination schedule
The HPV vaccination will be given as an injection into the muscle of your child’s upper arm, or thigh. Three doses are needed. If your child does not have all three injections, they may not be fully protected again the virus.
The second injection will be given between 1-2 months after the first injection, and your child will receive the third injection about six months after the first. However, it is possible for this dosing schedule to be more flexible. Your GP will be able to provide you with more information about this.
The HPV vaccine is given on its own, and is not combined with other vaccines, or solutions.
Side effects of HPV vaccination
Following clinical trials, the vaccine used in the UK HPV vaccination programme (Cervarix) was shown to cause side effects in some people.
Common side effects
The most commonly reported side effects are:
- mild to moderate swelling, and
- pain and redness at the injection site.
Other, mild side effects that have been reported include:
- a mild temperature,
- nausea and sickness,
- diarrhoea, and
- muscle aches.
Speak to your GP, or pharmacist, if your child’s side effects get worse, or they have any side effects other than those listed above.
Mild allergic reactions
In rare cases, shortly after having the vaccine, your child may experience an allergic reaction in the form of a skin rash, or itching. If they have a slight allergic reaction to the vaccine, the healthcare professional who gave them the injection will know how treat it. They should still continue to receive further HPV vaccinations.
Severe allergic reactions
In very rare cases, it is possible for someone who has the vaccine to experience a more severe allergic reaction, known as an anaphylactic reaction. Signs of an anaphylactic reaction include difficulty breathing and collapse.
However, it should be stressed that severe reactions of this nature are very rare and, when they do occur, the health professional who is giving the vaccine will have been fully trained in how to effectively deal with it. If your child has an anaphylactic reaction following treatment, they will usually fully recover within a few hours.
Cautions and considerations
Age and length of protection
The HPV vaccine is not recommended for children who are below 10 years of age.
Research has shown that the HPV vaccine’s protection is effective for four-and-a-half years after completing the three dose course. Beyond that, it is not known how long the vaccine’s protection will last.
Before being vaccinated, you should tell your GP if your child is taking, or has recently taken, any other medicines. For example, the vaccine may not work effectively when used with medicines that suppress your child’s immune system, such as regular steroids. You should also tell your GP if your child is taking, or has recently taken, any over-the-counter (OTC) medicines.
Research shows that taking hormonal contraceptives, such as the pill, does not appear to reduce the protection that the vaccine provides.
Research is continuing into areas such as:
- how long the HPV vaccine provides protection for, and whether further booster doses will be needed,
- whether vaccination against specific types of HPV provide protection against other types that are not covered by the vaccination (cross-protection),
- whether other types of HPV may take over as causes of cervical cancer, and
- links between HPV infection and other cancers - for example, anal cancer, or head and neck cancers, which may be associated with anal, or oral, sex.