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AIDSinfo Drug Database

AIDSinfo Drug Database

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Varicella Zoster Immune Globulin (Human)  Audio icon

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

What is VariZIG?

VariZIG is approved by the U.S. Food and Drug Administration (FDA) for reducing the severity of varicella zoster virus (VZV) infections (chicken pox infections) in high-risk people who have been exposed to the virus. This is called post-exposure prophylaxis (PEP). Examples of high-risk people include premature infants, adults with no immunity to VZV, and immunocompromised children and adults. (Immunocompromised means a person’s immune system cannot fight infections normally.) When high-risk people without immunity to VZV are exposed to the virus, they can experience severe and sometimes fatal infections. 

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 (a type of protein that the immune system makes), and other proteins. VariZIG contains high levels of antibodies that can fight against VZV.

VZV infection is an opportunistic infection. An opportunistic infection is an infection that occurs more frequently or is more severe in people with weakened immune systems—such as those infected with HIV—than in people with healthy immune systems.

What HIV-related opportunistic infections is VariZIG used for?

The Guidelines for the Prevention and Treatment of Opportunistic Infections in HIV-Infected Adults and Adolescents, prepared by the Centers for Disease Control and Prevention (CDC), the National Institutes of Health (NIH), and the HIV Medicine Association of the Infectious Diseases Society of America (IDSA-HIVMA), includes recommendations on the use of VariZIG for post-exposure prophylaxis (PEP) of VZV in HIV-infected individuals.

The above paragraph may not include all of the HIV-related uses of VariZIG recommended in the Guidelines for the Prevention and Treatment of Opportunistic Infections in HIV-Infected Adults and Adolescents. 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?

Before receiving VariZIG, tell your health care provider:

  • 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, for example, diabetes or liver problems. 
  • 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 are infected with 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?

A health care provider gives VariZIG as an injection. VariZIG is given as soon as possible after exposure to VZV, ideally within 96 hours of exposure for the greatest effectiveness. One dose of VariZIG is injected into a muscle in the upper arm or upper thigh. A second dose of VariZIG may be given to someone who has had additional exposures to VZV more than 3 weeks after the initial dose. Read any printed information that your health care provider gives you 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: June 14, 2015

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