Lancet：默沙东埃博拉疫苗rVSV-ZEBOV三期研究取得重要进展！

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2014年爆发在非洲的埃博拉疫情震惊了全世界，这也是有史以来爆发的最为严重的埃博拉疫情。在这次疫情中，世界各国政府纷纷意识到了传染病对人类健康的巨大威胁。因此，多个国家和众多国际医药巨头纷纷开始投入巨大人力物力进行埃博拉特效疗法和相关疫苗的研发。

最近，美国默克（北美地区外称为默沙东）宣布了其开发的埃博拉疫苗rVSV-ZEBOV临床三期研究中期数据分析结果。据了解，此次临床研究主要在埃博拉疫情重灾区几内亚进行，目前已经有4000名志愿者参与到此次名为“Ebola, that's enough”的临床研究。而WHO、几内亚卫生部等政府部门也参与其中。在几内亚进行的埃博拉病毒疫苗早期测试结果，今天发表在柳叶刀杂志上。其中，和埃博拉患者密切联系的4000人，被分为2组，其中一组的2000人被立即接种埃博拉病毒疫苗，另外一组在3周之后再接种疫苗，立即接种疫苗的2000人没有人发病，而三周之后接种的2000人当中有16例埃博拉病人。这一中期分析的结果表明，名为rVSV-ZEBOV的埃博拉病毒疫苗，可能非常有效和安全地预防埃博拉病毒。结果显示，该疫苗单剂量的有效性为100%（95%CI：74.7 - 100%; p=0.0036）。在接种疫苗的6-10天内可以有效预防埃博拉病毒的感染。

这些结果并不意味着世界现在马上就有一个埃博拉病毒疫苗。该疫苗需要经过进一步的安全性和功效测试。目前，该疫苗也开放给一线卫生工作者进行测试，无国界医生组织在声明中表示，这些医生不知疲倦地工作，并冒着生命危险每天照顾埃博拉病人，如果疫苗是有效的，那么我们已经保护他们免受病毒侵袭。

rVSV-ZEBOV的研受到了加拿大卫生部门的大力支持。在此次埃博拉疫情爆发的时候，默沙东就迅速进行了相关研究。rVSV-ZEBOV是基于NewLink Genetics Corporation授权的新技术为基础进行开发的。研究人员移除了埃博拉病毒中的一个重要基因，从而降低了这种病毒的毒力。研究表明人体的免疫系统能够对疫苗反应从而产生相应抗体，不仅能够帮助埃博拉感染患者还能预防二次感染。不过目前尚没有研究数据表明这种免疫反应能够持续的时间。截止到目前为止，已经有超过9000名志愿者参与到rVSV-ZEBOV疫苗的临床I、II、III期研究中。相信，人类彻底征服埃博拉已经为期不远。

（生物谷Bioon.com）

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Merck's Ebola vaccine is 100% successful in interim Phase III results

Merck's ($MRK) Ebola vaccine, in development alongside NewLink Genetics ($NLNK), protected 100% of patients from contracting the virus in interim results from an ongoing study, giving rise to hopes it can help prevent future outbreaks.

The vaccine, rVSV-ZEBOV, is in the midst of a big Phase III trial in West Africa, home to the most recent--and deadliest--outbreak of Ebola. In an interim analysis published in The Lancet, every patient who received the vaccine after Ebola broke out in his or her village was virus-free within 6 to 10 days, Merck said, suggesting rVSV-ZEBOV could be a highly effective option for stemming the spread of Ebola.

In a novel trial design, rVSV-ZEBOV's investigators decided against a traditional placebo-controlled trial in favor of a so-called ring study. The researchers identified 7,651 people in Guinea at risk for infection and split them into two groups: Roughly half would receive rVSV-ZEBOV immediately after exposure to Ebola and the rest would get the vaccine after a delay. In the interim analysis, the immediate group reported no infections after 10 days compared with 16 cases of Ebola in the other arm, a highly statistically significant result for rVSV-ZEBOV.

The study, sponsored by the World Health Organization and a slew of global entities, is still ongoing, but the randomization period is over and all patients will from here on out get immediate doses of the vaccine. The investigators are also still assessing its safety, noting that there have been just 43 adverse events in the Phase III study so far.

The vaccine's clinical success suggests it "may be the silver bullet against Ebola," Norway Foreign Minister Børge Brende told The Guardian, "helping to bring the current outbreak to zero and to control future outbreaks of this kind."

The latest Ebola outbreak resulted in nearly 30,000 cases in West Africa over the past year, leading to more than 11,000 reported deaths. And while rates of infection have tailed off over the past few months, rVSV-ZEBOV's developers are hopeful their vaccine could be key to heading off the next outbreak, or at least curtailing its severity.

http://www.fiercebiotech.com/sto ... -results/2015-07-31

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Efficacy and effectiveness of an rVSV-vectored vaccine expressing Ebola surface glycoprotein: interim results from the Guinea ring vaccination cluster-randomised trial

Ana Maria Henao-Restrepo, Ira M Longini, Matthias Egger, Natalie E Dean, W John Edmunds, Anton Camacho, Miles W Carroll, Moussa Doumbia, Bertrand Draguez, Sophie Duraffour, Godwin Enwere, Rebecca Grais, Stephan Gunther, Stefanie Hossmann, Mandy Kader Kondé, Souleymane Kone, Eeva Kuisma, Myron M Levine, Sema Mandal, Gunnstein Norheim, Ximena Riveros, Aboubacar Soumah, Sven Trelle, Andrea S Vicari, Conall H Watson, Sakoba Kéïta, Marie Paule Kieny*, John-Arne Røttingen*

Background A recombinant, replication-competent vesicular stomatitis virus-based vaccine expressing a surface glycoprotein of Zaire Ebolavirus (rVSV-ZEBOV) is a promising Ebola vaccine candidate. We report the results of an interim analysis of a trial of rVSV-ZEBOV in Guinea, west Africa.

Findings Between April 1, 2015, and July 20, 2015, 90 clusters, with a total population of 7651 people were included in the planned interim analysis. 48 of these clusters (4123 people) were randomly assigned to immediate vaccination with rVSV-ZEBOV, and 42 clusters (3528 people) were randomly assigned to delayed vaccination with rVSV-ZEBOV. In the immediate vaccination group, there were no cases of Ebola virus disease with symptom onset at least 10 days after randomisation, whereas in the delayed vaccination group there were 16 cases of Ebola virus disease from seven clusters, showing a vaccine efficacy of 100% (95% CI 74·7–100·0; p=0·0036). No new cases of Ebola virus disease were diagnosed in vaccinees from the immediate or delayed groups from 6 days post-vaccination. At the cluster level, with the inclusion of all eligible adults, vaccine effectiveness was 75·1% (95% CI –7·1 to 94·2; p=0·1791), and 76·3% (95% CI –15·5 to 95·1; p=0·3351) with the inclusion of everyone (eligible or not eligible for vaccination). 43 serious adverse events were reported; one serious adverse event was judged to be causally related to vaccination (a febrile episode in a vaccinated participant, which resolved without sequelae). Assessment of serious adverse events is ongoing


http://www.thelancet.com/pb/assets/raw/Lancet/pdfs/S0140673615611175.pdf