2012年12月21日美國食品藥品監(jiān)督管理局(FDA)批準(zhǔn)Varizig可用于治療水痘，高危患者在感染水痘帶狀皰疹病毒（VZV）4天后可使用Varizig緩解癥狀。

    Varizig是一種水痘帶狀皰疹免疫球蛋白制備物，由加拿大溫伯尼市的Cangene公司生產(chǎn)。Varizig是一類免疫球蛋白制劑，是目前FDA批準(zhǔn)的唯一可用于VZV感染的免疫球蛋白，同時它還被指定為孤兒藥物，可得到優(yōu)先批準(zhǔn)。

    VZV在兒童中引起水痘，在成年人群中引起帶狀皰疹。在美國大多數(shù)人可通過接種疫苗或兒童時期患過水痘而獲得對VZV的免疫力。但是，對VZV沒有免疫力的人們，如免疫低下的兒童和成人、妊娠婦女及妊娠期或產(chǎn)后暴露的嬰兒，當(dāng)他們暴露于VZV后可能導(dǎo)致嚴(yán)重感染甚至?xí)猩ｋU。有時候，對VZV沒有免疫力的健康人群也會發(fā)生嚴(yán)重感染，而抗病毒治療并非總能奇效，而且在某些情況下不能使用抗病毒治療。

    美國FDA藥物評價和研究中心主任Karen Midthun，M.D.說：“這個批準(zhǔn)滿足了降低易感VZV患者發(fā)生致死性感染風(fēng)險的緊迫要求。”

    Varizig是從高VZV抗體水平的健康捐獻(xiàn)者血漿中提取出來的一種抗體制劑，捐獻(xiàn)者的血漿均是從FDA認(rèn)證批準(zhǔn)的美國和加拿大的采集中心所抽取。當(dāng)易感患者暴露于VZV96小時之內(nèi)，可根據(jù)患者的體重，給予Varizig注射兩次或兩次以上。Varizig被批準(zhǔn)用于免疫力缺陷的兒童和成人、新生兒，妊娠婦女、早產(chǎn)嬰兒、1歲以內(nèi)的嬰兒和對VZV無免疫力的健康成人。

    水痘帶狀皰疹免疫球蛋白可降低早期暴露后嚴(yán)重感染的風(fēng)險。2006年FDA批準(zhǔn)的一個VZIG被制造商從美國市場去除，Varizig在申請獲得許可期間過程曾經(jīng)大量擴(kuò)展研究才獲得批準(zhǔn)。

    研究顯示Varizig與VZIG同樣的作用，在預(yù)防妊娠期間感染的療效與VZIG相同，易感個體使用Varizig治療后發(fā)生眼腫感染的機(jī)率低于未使用Varizig的易感個體。Varizig的使用是安全的，最常見副作用是注射部位疼痛和頭痛。

    英文文獻(xiàn)閱讀：

    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.