How does it work?

Gardasil is a vaccine against the human papilloma virus (HPV).This virus is asexually-transmitted infection that can cause genitalwarts, pre-cancerous abnormalities of cells in the female genitals (cervix orvulva) and cervical cancer. The vaccine works by provoking the body's immuneresponse to this virus, without actually causing HPV infection or any of thediseases.

When the body is exposed to foreign organisms, such asviruses and bacteria, the immune system producesantibodies against them. Antibodies help the body recognise and kill theforeign organisms. They then remain in the body to help protect the bodyagainst future infections with the same organism. This is known as activeimmunity.

The immune system produces different antibodies for each foreignorganism it encounters. This establishes a pool of antibodies that helpsprotect the body from various different diseases.

Vaccines contain extracts or inactivated forms of bacteria orviruses that cause disease. These altered forms of the organisms stimulate theimmune system to produce antibodies against them, but don't actually causedisease themselves. The antibodies produced remain in the body so that if theorganism is encountered naturally, the immune system can recognise it andattack it, thus preventing it from causing disease.

Each virus or bacteria stimulates the immune system to produce aspecific type of antibody. This means that different vaccines are needed toprevent different diseases.

Gardasil contains inactivated extracts from four different typesof the human papilloma virus: types 6, 11, 16 and 18. HPV types 16 and 18 areresponsible for approximately 70 per cent of cervical cancer cases and HPVtypes 6 and 11 are responsible for approximately 90 per cent of genital wartcases. Gardasil stimulates the immune system to produce antibodies againstthese types of the virus and is given to prevent the diseases that they cancause.

The vaccine is given by injection into the muscle of the upperarm or upper thigh. Three doses are needed and one of two schedules can beused. Either the first two doses are given two months apart and the third dosesix months after the first dose, or the first two doses are given at least onemonth apart with the third dose at least three months after the second dose.All three doses should be given within a one year period.

At the moment it is not known exactly how long the protectiveeffect of the vaccine will last for. Long term follow-up studies into this areongoing.

What is it used for?

Prevention of the following diseases caused by the humanpapilloma virus (HPV) types 6, 11, 16, and 18:

• genital warts
• pre-cancerous abnormalities of cells in the cervix (CIN 2/3), vulva (VIN 2/3) or vagina (VaIN2/3ix)
• cervical cancer.

The vaccine has been shown in clinical trials to prevent thesediseases in adult women aged 16 to 26 years. The vaccine has also been shown toproduce antibodies against HPV in children and adolescents aged 9 to 15 years.It is not known if these antibodies will prevent HPV disease in adult males.

Warning!

• This vaccine may not provide protection against HPV in everyone who has the vaccine. It will also only provide protection against HPV types 6, 11, 16, and 18. It will not protect against any other sexually-transmitted infections (STIs). This means that after having the vaccine you should still practice safe sex and use condoms to prevent STIs.
• This vaccine should not be used as an alternative to having regular cervical smear tests. This is because no vaccine is 100 per cent effective and this vaccine will not provide protection against types of HPV that are not in the vaccine. It also won't protect you from any cancerous changes that may be caused by an HPV infection you may already have. It is important to keep having regular smear tests.
• People who have an underactive immune system, for example due to a genetic defect, disease such as HIV infection, or treatment with immunosuppressant medicines such as chemotherapy, high-dose corticosteroids, or immunosuppressants, eg used following an organ transplant, may not produce an adequate number of antibodies in response to this vaccine. As a result, the vaccine may be less effective in these people.

Use with caution in

• People at risk of bleeding after an injection into a muscle, for example due to blood clotting disorders such as haemophilia or a reduced platelet count in the blood (thrombocytopenia).

Not to be used in

• Sudden feverish illness. (The vaccine should be postponed until after recovery.)
• This vaccine is not recommended for children under nine years of age, as its safety and effectiveness have not been studied in this age group.

This vaccine should not be used if you are allergic to one orany of its ingredients. Please inform your doctor or pharmacist if you havepreviously experienced such anallergy.If you feel you haveexperienced an allergic reaction after having this vaccine inform yourdoctor or pharmacist immediately.

Pregnancy and breastfeeding

Certain vaccines should not be given during pregnancy orbreastfeeding. However, other vaccines may be safely used in pregnancy orbreastfeeding providing the benefits to the mother outweigh any risks to theunborn baby. Always inform your doctor if you are pregnant or planning apregnancy, before having any vaccine or using any medicine.

• As the safety of this vaccine during pregnancy has not been fully established, it is recommended that it is not given to pregnant women. Instead it should be postponed until after the pregnancy is over. Seek further advice from your doctor.
• This vaccine can be given to women who are breastfeeding. It has not been shown to have any effect on a nursing infant, or to be any less effective in women who are breastfeeding.

Side effects

This vaccine contains no live virus and so cannot causeinfection with HPV or any of the diseases HPV can cause.

Vaccines and their possible side effects can affect individualpeople in different ways. The following are some of the side effects that areknown to be associated with this vaccine. Just because a side effect is stated here does not mean that all people receiving this vaccine will experience that orany side effect.

Very common (affect more than 1 in 10 people)

• Pain, redness or swelling at the injection site.
• Fever.

Common (affect between 1 in 10 and 1 in 100 people)

• Bruising or itching at the injection site.

Rare (affect between 1 in 1000 and 1 in 10,000 people)

• Itchy skin rash (hives).

Very rare (affect less than 1 in 10,000 people)

• Narrowing of the airways, as occurs in an asthma attack (bronchospasm).

Unknown frequency (reported since the vaccine has been on the market)

• Swollen glands.
• Nausea and vomiting.
• Dizziness.
• Fainting.
• Headache.
• Aching muscles or joints.
• Feeling weak, tired or generally unwell.
• Allergic reactions.

The side effects listed above may not include all of the sideeffects reported by the vaccine'smanufacturer.For moreinformation about any other possible risks associated with this vaccine, pleaseread the information provided with the vaccine or consult your doctor orpharmacist.

How can this vaccine affect other medicines?

People taking medicines that suppress the activity of the immunesystem, for example chemotherapy, high-dose corticosteroids, orimmunosuppressants, eg used following an organ transplant, may not produce adequatenumbers of antibodies in response to this vaccine. As a result, the vaccine maybe less effective in these people.

This vaccine can be safely given at the same time as thehepatitis B vaccine. If given at the same time, these vaccines should be giveninto different limbs.

This vaccine can be safely given to women taking oralcontraceptives.

The effect of giving this vaccine at the same time as any othervaccines, or in combination with any other medicines has not been studied. Youshould let your doctor know if you are taking any medicines, or have recentlyhad any other vaccines, or have recently been given immunoglobulin or otherblood products, before you are given this vaccine.

Other vaccines containing the same active ingredient

Cervarixis another brand of human papilloma virus (HPV) vaccine. It contains two types of HPV and is used to prevent cervical cancer. These two vaccines are not interchangeable. Your three dose vaccine course should be completed with the same brand of HPV vaccine, ie, if you receive your first injection with Gardasil, the next two injections to complete the vaccine course should also be with Gardasil.