Gardasil

Indications

The quadrivalent human papillomavirus (HPV) vaccine protects against four types of HPV: types 6, 11, 16 and 18. It is used from 9 years of age in girls and women, and in boys and men, to help prevent cervical cancer and pre-cancerous changes of the cervix, vulva, vagina and anus caused by HPV types 16 and 18, and genital warts caused by types 6 and 11. It works best when given before any exposure to HPV, so it is ideally given before sexual activity starts.

How It Works

The vaccine contains virus-like particles made from the outer shell protein of the four HPV types. These particles look like the virus to the immune system but contain no viral genetic material, so they cannot cause infection or cancer. The body makes protective antibodies that can block the real virus if exposure happens later. It does not treat existing HPV infection, warts or cancer.

Dosage and Administration

The vaccine is given by a doctor or nurse as an injection into the muscle of the upper arm or thigh. The number of doses and the gap between them depend on age and national guidelines, as set by the doctor or vaccination programme: younger children often need two doses, while older teenagers and adults usually need three. Complete the full schedule for best protection.

Interactions

It can be given at the same visit as several other vaccines, using a different injection site. People taking medicines that weaken the immune system (such as high-dose corticosteroids, chemotherapy or transplant medicines) may have a weaker response. Hormonal contraceptives do not affect it.

Contraindications

• Severe allergic reaction to a previous dose or to any component of the vaccine, including yeast
• Vaccination should be postponed during a high fever or acute severe illness; a minor cold is not a reason to delay

Side Effects

Common effects include pain, swelling, redness or itching at the injection site, headache, fever, nausea, dizziness and tiredness. Fainting can occur shortly after any injection, especially in teenagers, so the person should sit or lie down and be observed for about 15 minutes after vaccination.

Get urgent medical help for signs of a severe allergic reaction (difficulty breathing, swelling of the face or throat, widespread rash, collapse), or for unusual weakness or numbness in the limbs.

Pregnancy and Lactation

Vaccination is not recommended during pregnancy; if a woman becomes pregnant during the schedule, the remaining doses are delayed until after pregnancy. No harm has been seen when the vaccine was given by mistake in pregnancy. It can be given to breastfeeding women.

Precautions and Warnings

The vaccine does not protect against all HPV types or other sexually transmitted infections, so regular cervical screening is still needed for women. Use with care in people with bleeding disorders or low platelets because of the injection into muscle. Protection may be weaker in people with a weakened immune system.

Overdose

Extra doses given in error are not expected to cause harm beyond the usual side effects.

Therapeutic Class

Vaccine; recombinant human papillomavirus vaccine (quadrivalent).

Storage

Store in a refrigerator at 2 to 8°C, do not freeze, and keep in the original package to protect from light. Keep out of the reach of children.