2015年4月15日讯 /生物谷BIOON/ --默沙东（Merck & Co）和合作伙伴NewLink Genetics近日证实，已在塞拉利昂（Sierra Leone）启动了实验性埃博拉疫苗rVSV-ZEBOV-GP（V920）的第三个后期临床试验。这也标志着默沙东的疫苗在埃博拉疫情最严重的3个西非国家（塞拉利昂、利比里亚、几内亚）全面进入III期临床。
在塞拉利昂开展的大型II/III期研究名为STRIVE，涉及6000名卫生及其他一线工作人员，将调查rVSV-ZEBOV-GP的安全性和有效性。在利比里亚开展的研究名为PREVAIL，涉及大约2.7万名健康成人志愿者，将调查rVSV-ZEBOV-GP和另一种实验性埃博拉疫苗的安全性和有效性；由于利比里亚埃博拉发病率已经下降，研究人员正在考虑适当扩大试验，将西非国家的其他站点纳入研究，目前还在讨论中。在几内亚开展的III期研究已于3月底在重灾社区启动疫苗的接种工作，计划在6-8周内，对大约1万人开展疫苗接种，调查rVSV-ZEBOV-GP的安全性和有效性。
根据世界卫生组织（WHO）的最新数据，截止4月5日，在埃博拉主要疫情国塞拉利昂、利比里亚、几内亚累计发现疑似及确诊埃博拉病例25515例，死亡人数10572人。不过，近几个月来这3个国家的埃博拉疫情已趋平缓。
默沙东-NewLink合作开发的候选疫苗疫苗rVSV-ZEBOV-GP，最初是由加拿大公共卫生署（PHAC）开发，之后在2010年授权给了NewLink。去年11月，默沙东与NewLink签署一项全球独家授权协议，加入埃博拉疫苗研发阵营。rVSV-ZEBOV-GP采用了一种有缺陷的、能够感染家畜的水泡性口炎病毒，将病毒的一种基因用埃博拉病毒的基因替换。根据目前所获得的数据，该疫苗的安全性良好。
关于埃博拉（Ebola）：
埃博拉病毒（Ebola）是导致埃博拉出血热（EHF）的元凶，该病是一种急性病毒性出血性传染病，症状包括：发烧、头痛、关节和肌肉疼痛、乏力、腹泻、呕吐、胃痛、食欲不振及异常出血。这些症状可在病毒感染后2-21天内出现，但最常见于8-10天。埃博拉病毒不是一种经水传播（water-borne）或食物传播的疾病，也不通过空气传播，该病通过直接接触受感染者体液或已被病毒污染的器具（如针头）传播。
英文原文：Phase III Trial of the Merck and NewLink Genetics Investigational Ebola Vaccine Initiated in Sierra Leone
rVSV-ZEBOV-GP (V920) Now Being Studied in Three Key Safety and Efficacy Clinical Trials
KENILWORTH, N.J. & AMES, Iowa--(BUSINESS WIRE)--Merck (NYSE:MRK), known as MSD outside the United States and Canada, and NewLink Genetics Corporation (NASDAQ: NLNK), confirmed today that the third, late-stage, clinical trial of their Ebola vaccine candidate rVSV-ZEBOV-GP (V920) has been initiated in Sierra Leone. The vaccine candidate was originally developed by the Public Health Agency of Canada’s National Microbiology Laboratory and licensed to NewLink Genetics in 2010. On Nov. 24, 2014, Merck and NewLink Genetics announced an exclusive licensing and collaboration agreement for the investigational Ebola vaccine.
The Phase II/ III safety and effectiveness study, called STRIVE (Sierra Leone Trial to Introduce a Vaccine against Ebola) taking place in Sierra Leone will involve 6,000 health and other frontline workers and is being led by the Sierra Leone College of Medicine and Allied Health Sciences, Sierra Leone Ministry of Health and Sanitation, and the U.S. Centers for Disease Control and Prevention (CDC).
“Fighting Ebola remains a global health priority, and Merck is committed to advancing the development of our and NewLink’s vaccine candidate as part of our overall response to the crisis,” said Mark Feinberg, M.D., Ph.D., chief public health and science officer, Merck Vaccines.
The Merck and NewLink rVSV-ZEBOV-GP vaccine candidate is now included in three large-scale clinical trials currently underway in West Africa. In addition to the trial in Sierra Leone, these trials are:
The Partnership for Research on Ebola Vaccines in Liberia (PREVAIL): Led by a Liberia-U.S. clinical research partnership and sponsored by the National Institute of Allergy and Infectious Diseases (NIAID), PREVAIL was designed to enroll approximately 27,000 healthy men and women aged 18 years and older. This randomized, controlled Phase II/III study to evaluate safety and efficacy, involves rVSV-ZEBOV-GP and another experimental Ebola vaccine. Based on declining Ebola virus incidence in Liberia, the trial leaders have determined that it is scientifically appropriate to expand the trial to additional sites in other West African countries. Discussions are underway to explore that possibility, but the trial has not yet expanded outside of Liberia.
Phase III study in Guinea: The World Health Organization (WHO), the Health Ministry of Guinea, Médecins sans Frontières (MSF), Epicentre and The Norwegian Institute of Public Health have initiated a safety and effectiveness study investigating Merck’s and NewLink’s rVSV-ZEBOV-GP, the vaccine candidate that was selected by the WHO and study partners to be assessed first in this study.