Varicella zoster (commonly known as chickenpox) is a common childhood disease that causes fever, skin rash, and a breakout of fluid-filled blisters on the skin. Chickenpox is usually mild, but it can be serious or even fatal in young infants, in adults, and in people who have a weak immune system. It can lead to severe skin infection, breathing problems, brain damage, or death.

When varicella zoster virus becomes active again in an adult, it can cause herpes zoster (also called shingles) which causes painful blisters, skin infections, severe nerve pain, and hearing or vision problems that can last for months or years.

Chickenpox is spread from person to person through the air, or by coming into contact with the fluid from a chickenpox blister.

Varizig is used in adults, children, and babies (including newborn or premature infants) who could become severely ill from exposure to varicella zoster virus. Varizig is also for use in pregnant women.

Varizig is used after exposure in people who have already come into contact with varicella virus. This medicine can help keep symptoms of the virus from becoming severe or life-threatening.

This medicine will not treat an active infection that has already developed in the body.

Varizig may also be used for purposes not listed in this medication guide.

Follow all directions on your medicine label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.

Varizig is injected into a muscle. A healthcare provider will give you this injection.

Varizig should be given as soon as possible (within 96 hours) after you have been exposed to varicella zoster virus.

This medicine is usually given only once. However, in some cases your doctor may recommend a second dose, especially if you are re-exposed to varicella zoster virus more than 3 weeks after your immune globulin injection.

A single dose may need to be injected into more than one place on your body, depending on your size. Varizig doses are based on weight.

You should not be treated with Varizig if:

• you have had an allergic reaction to an immune globulin; or

• you have immune globulin A (IgA) deficiency with antibody to IgA.

Tell your doctor if you have recently received a "live" vaccine. The vaccine may not work as well shortly after you receive Varizig. Live vaccines include measles, mumps, and rubella (MMR), polio, rotavirus, typhoid, yellow fever, varicella (chickenpox), zoster (shingles), and nasal flu (influenza) vaccine.

To make sure Varizig is safe for you, tell your doctor if you have:

• heart disease, coronary artery disease (hardened arteries);

• a bleeding or blood clotting disorder;

• blood circulation problems;

• a history of stroke or blood clot; or

• a condition for which you are on bed rest.

It is not known whether Varizig will harm an unborn baby. However, chickenpox can cause birth defects, low birth weight, or a serious infection in the newborn. Therefore, this medicine may be given during pregnancy if you have a high risk of infection with varicella zoster virus.

It is not known whether varicella zoster immune globulin passes into breast milk or if it could harm a nursing baby. Tell your doctor if you are breast-feeding a baby.

Varizig is made from human plasma (part of the blood) which may contain viruses and other infectious agents. Donated plasma is tested and treated to reduce the risk of it containing infectious agents, but there is still a small possibility it could transmit disease. Talk with your doctor about the risks and benefits of using this medication.

Since Varizig is usually given only once, you are not likely to miss a dose. Contact your doctor if you do not receive all recommended doses.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Varizig may cause serious side effects. Call your doctor at once if you have:

• signs of a blood clot in the brain--sudden numbness or weakness (especially on one side of the body), slurred speech, problems with vision or balance;

• signs of a blood clot in the heart or lung--chest pain, rapid heart rate, sudden cough, wheezing, rapid breathing, coughing up blood;

• signs of a blood clot in your leg--pain, swelling, warmth, or redness in one or both legs; or

• signs of a new infection--fever, chills, flu symptoms, mouth sores, pain when swallowing.

Side effects may be more likely in older adults.

Common side effects of Varizig may include:

• headache; or

• pain where the medicine was injected.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Other drugs may interact with varicella zoster immune globulin, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.