Varizost

Indications

Varicella virus vaccine is used to protect against chickenpox (varicella). It is given to children from about 12 months of age, and to adolescents and adults who have not had chickenpox or the vaccine before, particularly those at higher risk of exposure or complications, such as health workers, close contacts of people with weak immunity, and women planning pregnancy.

How It Works

The vaccine contains a live but weakened form of the varicella-zoster virus. It causes no illness or only a very mild one, but it teaches the immune system to recognise the virus and make antibodies and immune cells against it. If the person is later exposed to chickenpox, the body can fight it off or the illness is usually much milder.

Dosage and Administration

The vaccine is given by a doctor or nurse as an injection under the skin (and with some products into the muscle), usually in the upper arm or thigh. Two doses are usually recommended, with the interval set by the national schedule or the doctor. It can also be given soon after exposure to chickenpox to help prevent or lessen the illness, as advised by a doctor.

Interactions

Avoid Aspirin and other salicylates for 6 weeks after vaccination in children and adolescents, because of the risk of Reye's syndrome. Blood products and immunoglobulins can reduce the response, so timing must be planned by the doctor. If not given on the same day, measles-containing vaccines and the varicella vaccine should be separated by at least 4 weeks. Antiviral medicines such as Aciclovir may reduce the vaccine's effect if taken around the time of vaccination. Tell the doctor about any medicine that weakens the immune system.

Contraindications

The vaccine must not be given to:

• Pregnant women
• People with weakened immunity, such as from leukaemia, lymphoma, untreated or advanced HIV, or high-dose corticosteroids, chemotherapy or other immune-suppressing treatment
• Anyone who had a severe allergic reaction to a previous dose or to any ingredient, including Gelatin or Neomycin
• People with active untreated tuberculosis or a high fever (vaccination is postponed)

Side Effects

Common side effects include:

• Pain, redness or swelling where the injection was given
• Mild fever
• A mild chickenpox-like rash with a few spots, at the injection site or elsewhere, within a few weeks
• Irritability or tiredness

Get urgent medical help for signs of a severe allergic reaction (swelling of the face or throat, difficulty breathing, widespread hives), fits, high fever, or a widespread blistering rash, especially in someone with weak immunity.

Pregnancy and Lactation

This vaccine must not be given during pregnancy, and pregnancy should be avoided for 1 month after each dose. Women who are breastfeeding can usually be vaccinated, and the vaccine may be given to non-immune mothers after delivery.

Precautions and Warnings

Tell the doctor about any immune problem, recent blood transfusion, or medicines taken. In rare cases the vaccine virus can spread from a vaccinated person who develops a rash; until the rash crusts over, avoid close contact with pregnant women who are not immune, newborn babies of non-immune mothers and people with very weak immunity. The vaccine does not protect everyone completely.

Overdose

Overdose is unlikely because the vaccine is given by health professionals. An extra dose given by mistake is not expected to cause serious harm; inform the doctor.

Therapeutic Class

Viral vaccine (live attenuated varicella vaccine).

Storage

Stored by the health facility as directed on the pack, usually in a refrigerator or freezer according to the product, protected from light. Keep out of the reach of children.