Manischewitz Jody, King Lisa R, Bleckwenn Nicole A, Shiloach Joseph, Taffs Rolf, Merchlinsky Michael, Eller Nancy, Mikolajczyk Malgorzata G, Clanton David J, Monath Thomas, Weltzin Richard A, Scott Dorothy E, Golding Hana
Division of Viral Products, Center for Biologics Evaluation and Research, Food and Drugs Administration, Bethesda, Maryland 20892, USA.
J Infect Dis. 2003 Aug 1;188(3):440-8. doi: 10.1086/376557. Epub 2003 Jul 16.
In anticipation of large-scale smallpox vaccination, clinical trials of new vaccine candidates with improved safety profiles, and new vaccinia immune globulin (VIG) products, there is an immediate need to develop new assays to measure vaccinia-specific immune responses. The classical assay to measure vaccinia neutralization, the plaque-reduction neutralization test (PRNT), is slow, labor intensive, and difficult to validate and transfer. Here we describe the development of a novel vaccinia-neutralization assay based on the expression of a reporter gene, beta-galactosidase (beta-Gal). Using a previously constructed vaccinia-beta-Gal recombinant virus, vSC56, we developed a neutralization assay that is rapid, sensitive, and reproducible. The readout is automated. We show that the neutralizing titers, ID(50), for several VIG products measured by our assay were similar to those obtained by PRNTs. A new Food and Drug Administration VIG standard was established for distribution to other laboratories. The new assay will serve as an important tool both for preclinical and clinical trials of new smallpox vaccines and for evaluation of therapeutic agents to treat vaccine-associated adverse reactions.
鉴于即将进行大规模天花疫苗接种、对具有更优安全性的新型候选疫苗以及新型牛痘免疫球蛋白（VIG）产品开展临床试验，当下迫切需要开发新的检测方法来测定牛痘特异性免疫反应。用于测定牛痘中和作用的经典检测方法，即蚀斑减少中和试验（PRNT），耗时久、劳动强度大，且难以验证和推广。在此，我们描述了一种基于报告基因β-半乳糖苷酶（β-Gal）表达的新型牛痘中和检测方法的开发过程。利用先前构建的牛痘-β-Gal重组病毒vSC56，我们开发了一种快速、灵敏且可重复的中和检测方法。检测结果可自动读取。我们发现，通过我们的检测方法测得的几种VIG产品的中和效价ID(50)与PRNT法测得的结果相似。美国食品药品监督管理局制定了一项新的VIG标准并分发给其他实验室。这种新的检测方法将成为新型天花疫苗临床前和临床试验以及评估治疗疫苗相关不良反应的治疗药物的重要工具。
