2012年12月21日美国食品药品监督管理局(FDA)批准Varizig可用于治疗水痘，高危患者在感染水痘带状疱疹病毒（VZV）4天后可使用Varizig缓解症状。

Varizig是一种水痘带状疱疹免疫球蛋白制备物，由加拿大温伯尼市的Cangene公司生产。Varizig是一类免疫球蛋白制剂，是目前FDA批准的唯一可用于VZV感染的免疫球蛋白，同时它还被指定为孤儿药物，可得到优先批准。

VZV在儿童中引起水痘，在成年人群中引起带状疱疹。在美国大多数人可通过接种疫苗或儿童时期患过水痘而获得对VZV的免疫力。但是，对VZV没有免疫力的人们，如免疫低下的儿童和成人、妊娠妇女及妊娠期或产后暴露的婴儿，当他们暴露于VZV后可能导致严重感染甚至会有生命危险。有时候，对VZV没有免疫力的健康人群也会发生严重感染，而抗病毒治疗并非总能奇效，而且在某些情况下不能使用抗病毒治疗。

美国FDA药物评价和研究中心主任Karen Midthun，M.D.说：“这个批准满足了降低易感VZV患者发生致死性感染风险的紧迫要求。”

Varizig是从高VZV抗体水平的健康捐献者血浆中提取出来的一种抗体制剂，捐献者的血浆均是从FDA认证批准的美国和加拿大的采集中心所抽取。当易感患者暴露于VZV96小时之内，可根据患者的体重，给予Varizig注射两次或两次以上。Varizig被批准用于免疫力缺陷的儿童和成人、新生儿，妊娠妇女、早产婴儿、1岁以内的婴儿和对VZV无免疫力的健康成人。

水痘带状疱疹免疫球蛋白可降低早期暴露后严重感染的风险。2006年FDA批准的一个VZIG被制造商从美国市场去除，Varizig在申请获得许可期间过程曾经大量扩展研究才获得批准。

研究显示Varizig与VZIG同样的作用，在预防妊娠期间感染的疗效与VZIG相同，易感个体使用Varizig治疗后发生眼肿感染的机率低于未使用Varizig的易感个体。Varizig的使用是安全的，最常见副作用是注射部位疼痛和头痛。

英文文献阅读：

FDA approves Varizig for reducing chickenpox symptoms

The U.S. Food and Drug Administration has approved Varizig for reducing the severity of chicken pox (varicella zoster virus) infections in high risk individuals when given within four days after exposure.

Varizig is a varicella zoster immune globulin preparation. Varicella zoster virus (VZV) causes chickenpox in children and shingles in adults. Varizig is the only FDA approved immune globulin for VZV after exposure available in the United States. It was designated as an orphan drug by the FDA and received a priority review.

Most people in the United States have immunity to VZV from vaccination or from having had chickenpox during childhood. However, people without immunity to VZV who are exposed to the virus may experience severe infections that are sometimes fatal.

People most at risk include children or adults with weakened immune systems, pregnant women, and infants exposed during pregnancy or after birth. Occasionally, healthy people without immunity to VZV may contract severe infections. Antiviral treatments are not always effective and cannot be used in some cases.

“This approval fills an unmet need by providing a treatment to lower the risk of severe, potentially fatal varicella infections in vulnerable patients,” said Karen Midthun, M.D., director of the FDA’s Center for Biologics Evaluation and Research.

Varizig is an antibody preparation manufactured from plasma of healthy donors with high anti-VZV antibody levels. The donated plasma comes from FDA-licensed collection facilities in the United States and Canada. Varizig is administered in two or more injections, depending on the weight of the recipient, within 96 hours after exposure. Varizig is approved for immuno-compromised children and adults, newborns, pregnant women, premature infants, children less than a year old, and adults with no immunity to VZV.

Varicella zoster immune globulin (VZIG) has been shown to lower the risk of severe infections if given soon enough after exposure. An earlier FDA-licensed VZIG was removed from the U.S. market by the manufacturer in 2006, and Varizig has only been available under an investigational expanded access protocol during the licensing process.

In studies Varizig was shown to be comparable to VZIG and was as effective as VZIG in preventing infection during pregnancy. Data on Varizig collected from individuals treated under the expanded access protocol showed a low rate of severe VZV infection in susceptible individuals compared with the rate in untreated individuals.

The studies also showed that Varizig is safe for its intended use, with the most common side effects being pain at the injection site and headache.

Varizig is manufactured by Cangene Corporation in Winnipeg, Canada.