HPvax

Indications

The bivalent human papillomavirus (HPV) vaccine protects against infection with HPV types 16 and 18, the two types responsible for most cases of cervical cancer. It is used to prevent cervical cancer and pre-cancerous changes of the cervix, and also helps protect against some other HPV-related cancers such as anal cancer. It is given to girls and young women, ideally before they become sexually active, and in some programmes to boys as well.

How It Works

The vaccine contains virus-like particles made from the outer protein of HPV types 16 and 18. These particles cannot cause infection or cancer, but they teach the immune system to make antibodies. If the person is later exposed to these HPV types, the antibodies prevent the virus from infecting the cells of the cervix and other areas. An added ingredient (adjuvant) strengthens the immune response.

Dosage and Administration

The vaccine is given by a doctor, nurse or trained health worker as an injection into the muscle of the upper arm. The number of doses and the gap between them depend on age and the national immunisation schedule; younger girls usually need fewer doses than older adolescents and adults. Follow the schedule set by your doctor or vaccination programme and complete all doses. It does not treat an existing HPV infection or cancer.

Interactions

It can usually be given at the same visit as 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 reduce its effect.

Contraindications

Do not give to anyone who had a severe allergic reaction to a previous dose or to any ingredient of the vaccine. Vaccination should be postponed in a person with a high fever or acute severe illness; a mild cold is not a reason to delay.

Side Effects

Common side effects include pain, redness and swelling at the injection site, headache, tiredness, muscle aches, mild fever, nausea or stomach upset, itching or rash. Fainting can happen after any injection, especially in teenagers, so the person should sit or lie down and be watched for about 15 minutes afterwards.

Get urgent medical help if signs of a serious allergic reaction occur, such as difficulty breathing, wheezing, swelling of the face or throat, widespread hives, a fast heartbeat or dizziness. Vaccination centres are equipped to treat these reactions.

Pregnancy and Lactation

Vaccination is usually postponed until after pregnancy as a precaution, although no harm has been shown if it is given by accident. If a woman becomes pregnant during the course, the remaining doses are given after delivery. It may be given during breastfeeding if the doctor advises.

Precautions and Warnings

• The vaccine does not protect against all HPV types, so regular cervical screening is still needed.
• It does not protect against other sexually transmitted infections.
• Tell the vaccinator about bleeding disorders or blood-thinning medicines, as bruising may occur after an injection into muscle.
• People with weakened immunity may not be fully protected.

Overdose

Overdose is unlikely because the vaccine is given by health professionals in single doses. Extra doses given by mistake have not been linked to harm beyond the usual side effects.

Therapeutic Class

Vaccine (human papillomavirus bivalent, types 16 and 18, recombinant, adjuvanted)

Storage

Store in a refrigerator at 2 to 8°C, do not freeze, and protect from light. Discard if frozen. Given by health professionals; keep out of the reach of children.