Drug information

Brand Name:
Other Names:
varicella zoster immune globulin
Drug Class:
Opportunistic Infections and Coinfections
What is VariZIG?What is VariZIG?

What is VariZIG?


VariZIG is approved by the U.S. Food and Drug Administration (FDA) for post-exposure prophylaxis (PEP) of varicella zoster virus (VZV) infection (also called varicella or chicken pox) in people at high-risk. People at high risk of varicella include pregnant women, premature infants, and children and adults who are immunocompromised. VariZIG is intended to reduce the severity of varicella if infection occurs.

VariZIG is made from blood plasma of healthy, screened human donors. Plasma is the fluid part of the blood that contains water, salts, enzymes, antibodies (specific proteins produced by the immune system when it detects harmful substances), and other proteins. VariZIG contains antibodies against VZV.

VZV infection is an opportunistic infection (OI) of HIV. An OI is an infection that occurs more frequently or is more severe in people with weakened immune systems—such as people with HIV—than in people with healthy immune systems. To learn more about opportunistic infections, read the ClinicalInfo What is an Opportunistic Infection? fact sheet.

How is VariZIG used in people with HIV?How is VariZIG used in people with HIV?

How is VariZIG used in people with HIV?


The Guidelines for the Prevention and Treatment of Opportunistic Infections in HIV-Infected Adults and Adolescents include recommendations on the use of VariZIG for PEP of VZV infection in people with HIV.

The above paragraph may not include all of the uses of VariZIG in people with HIV that are recommended in the guidelines. Some recommended uses, such as uses in certain rare circumstances, may have been omitted.

What should I tell my health care provider before receiving VariZIG?What should I tell my health care provider before receiving VariZIG?

What should I tell my health care provider before receiving VariZIG?

Before receiving VariZIG, tell your health care provider:

  • If you are allergic to VariZIG or any other medicines.
  • If you have ever had an anaphylactic reaction or a severe systemic allergic reaction to human immune globulin preparations.
  • If you are deficient in immunoglobulin A (IgA).
  • About any medical conditions you have or have had.
  • About anything that may prevent you from receiving medicine by injection.
  • If you are pregnant or plan to become pregnant. Whether VariZIG can harm an unborn baby is unknown. VariZIG should be given to a pregnant woman only if clearly needed. Talk to your health care provider about possible risks with taking VariZIG when pregnant.
  • If you are breastfeeding or plan to breastfeed. Do not breastfeed if you have HIV.
  • About other prescription and nonprescription medicines, vitamins, nutritional supplements, and herbal products you are taking or plan to take. VariZIG may affect the way other medicines or products work, and other medicines or products may affect how VariZIG works. Ask your health care provider if there are interactions between VariZIG and the medicines you take.

Ask your health care provider about possible side effects from VariZIG. Your health care provider will tell you what to do if you have side effects.

How is VariZIG given?How is VariZIG given?

How is VariZIG given?

VariZIG dosing is based on a person’s weight. The dose is divided and given by intramuscular injection. VariZIG is given as soon as possible after exposure to VZV, ideally within 96 hours of exposure for the greatest effectiveness. A person re-exposed to VZV more than 3 weeks after receiving VariZIG may get a second dose of the drug.

Where can I find more information about VariZIG?Where can I find more information about VariZIG?

Where can I find more information about VariZIG?

More information about VariZIG is available:


The above Patient Version drug summary is based on the following FDA label(s): Injection (sterile solution).


Last Reviewed: April 24, 2019