Drug information

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 chickenpox (also called varicella or primary varicella infection) in people at high-risk for severe disease, such as pregnant women, premature infants, and children and adults who are immunocompromised. VariZIG is intended to reduce the severity of chickenpox if infection occurs.

Chickenpox can be 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 HIVinfo What is an Opportunistic Infection? fact sheet.

The Guidelines for the Prevention and Treatment of Opportunistic Infections in Adults and Adolescents with HIV and the Guidelines for the Prevention and Treatment of Opportunistic Infections in Children with and Exposed to HIV include recommendations on the use of VariZIG for post-exposure prophylaxis (PEP) of chickenpox in people with HIV.

The recommended uses may not always be consistent with FDA-approved uses of VariZIG. See the Adult and Pediatric Opportunistic Infection Guidelines for complete information on recommended uses of VariZIG in adults and children with HIV. VariZIG may have other recommended uses not listed above.

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.
  • About any medical conditions you have or have had, particularly:
    • 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 anything that may prevent you from receiving medicine by injection.
  • If you are pregnant or plan to become pregnant. Talk to your health care provider about the risks and benefits of receiving VariZIG during pregnancy. The Guidelines for the Prevention and Treatment of Opportunistic Infections in Adults and Adolescents with HIV may include other recommendations on the use of VariZIG during pregnancy. Please refer to these guidelines for additional information.
  • If you are breast/chestfeeding or plan to breast/chestfeed. For people with HIV in the United States, the Guideline recommends speaking with your health care provider to discuss options for feeding your baby. People with suppressed viral load have a less than 1% chance of transmitting HIV to their baby via their own milk.
  • 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. In people with HIV, VariZIG should be given as soon as possible and within 10 days after exposure to varicella-zoster virus (VZV). 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?

Last Reviewed: May 21, 2023