FDA Approval of an Extended Period for Administering VariZIG for Postexposure Prophylaxis of Varicella

VariZIG (Cangene Corporation, Winnipeg, Canada) is the only varicella zoster immune globulin preparation available in the United States for postexposure prophylaxis of varicella in persons at high risk for severe disease who lack evidence of immunity to varicella and are ineligible for varicella vaccine. VariZIG is available in the United States through an investigational new drug (IND) application expanded access protocol (1). VariZIG is a purified immune globulin preparation made from human plasma containing high levels of anti–varicella zoster virus antibodies (immunoglobulin G). In May 2011, the Food and Drug Administration (FDA) approved an extended period for administering VariZIG. The period after exposure to varicella zoster virus during which a patient may receive VariZIG, which had been 96 hours (4 days), is now 10 days (1). VariZIG should be administered as soon as possible after exposure.