被擱置了10年的埃博拉病毒疫苗大綱

GALVESTON, Texas — Almost a decade ago, scientists from Canada and the United States reported that they had created a vaccine that was 100 percent effective in protecting monkeys against the Ebola virus. The results were published in a respected journal, and health officials called them exciting. The researchers said tests in people might start within two years, and a product could potentially be ready for licensing by 2010 or 2011.

德克薩斯州加爾維斯頓——差不多10年前，加拿大和美國的科學家宣佈，他們研製出了一種可以保護猴子不被埃博拉病毒感染的疫苗，百分之百有效。其研究成果被髮表在了一本頗有聲望的期刊上；衛生官員們曾表示，該成果令人興奮。研究人員當時稱，可能會在兩年之內對疫苗進行人體測試；到2010年或者2011年，可能已經爲疫苗產品獲得許可做好了準備。

It never happened. The vaccine sat on a shelf. Only now is it undergoing the most basic safety tests in humans — with nearly 5,000 people dead from Ebola and an epidemic raging out of control in West Africa.

他們的話並未成真。該疫苗一度被束之高閣，直到現在纔開始進行最基本的人體測試——此時，已有近5000人死於埃博拉，西非地區疫情肆虐，失去了控制。

Its development stalled in part because Ebola is rare, and until now, outbreaks had infected only a few hundred people at a time. But experts also acknowledge that the lack of follow-up on such a promising candidate reflects a broader failure to produce medicines and vaccines for diseases that afflict poor countries. Most drug companies have resisted spending the enormous sums needed to develop products useful mostly to countries with little ability to pay.

該疫苗的研發之所以被擱置，在某種程度上是因爲埃博拉病毒非常罕見，而且以前每次爆發疫情，都只有數百人被感染。但業內人士也承認，沒能對這一頗有前途的候選藥品進行後續研究，映襯出了更大的失敗：窮國的民衆飽受某些疾病的折磨，但針對此類疾病的藥物或疫苗卻無法被生產出來。有些國家根本沒錢買藥，大部分製藥公司都不願投入大量資金去研製主要應用於這些國家的產品。

Now, as the growing epidemic devastates West Africa and is seen as a potential threat to other regions as well, governments and aid groups have begun to open their wallets. A flurry of research to test drugs and vaccines is underway, with studies starting for several candidates, including the vaccine produced nearly a decade ago.

眼下，由於不斷升級的疫情讓西非陷入了混亂，並被視爲對其他區的潛在威脅，各國政府和援助團體終於打開了自己的錢包。一連串旨在測試藥物和疫苗的研究正在進行之中，其研究對象包括一些候選藥品，如近10年前就已經被製造出來的那種疫苗。

A federal official said in an interview on Thursday that two large studies involving thousands of patients were planned to begin soon in West Africa, and were expected to be described in detail on Friday by the World Health Organization.

一位聯邦官員週四接受採訪時說，按照計劃，兩項涉及數千名患者的大型研究很快就會在西非啓動，世界衛生組織(World Health Organization)將於週五公佈相關細節。

With no vaccines or proven drugs available, the stepped-up efforts are a desperate measure to stop a disease that has defied traditional means of containing it.

由於沒有疫苗或者經過驗證的藥物可用，大力推進研究工作實際上是爲了阻止這種疾病的蔓延而採取的非常手段——使用傳統的治療方式已經無法控制它了。

"There's never been a big market for Ebola vaccines," said Thomas W. Geisbert, an Ebola expert here at the University of Texas Medical Branch in Galveston, and one of the developers of the vaccine that worked so well in monkeys. "So big pharma, who are they going to sell it to?" Dr. Geisbert added: "It takes a crisis sometimes to get people talking. ‘O.K. We've got to do something here.' "

“埃博拉疫苗的市場需求一直不大，”德克薩斯大學加爾維斯頓醫學分部(University of Texas Medical Branch in Galveston)的埃博拉病毒專家托馬斯·W·蓋斯伯特(Thomas W. Geisbert)說。他同時也是那種對猴子很有效的埃博拉疫苗的研發者之一。“如果大量生產，他們要賣給誰呢？”蓋斯伯特補充說：“有時候只有危機來臨，才能引發人們的討論。‘好吧，我們得做點什麼了。'”

Dr. James E. Crowe Jr., the director of a vaccine research center at Vanderbilt University, said that academic researchers who developed a prototype drug or vaccine that worked in animals often encountered a "biotech valley of death" in which no drug company will help them cross the finish line.

範德比爾特大學(Vanderbilt University)某疫苗研究中心的主任小詹姆斯·E·克勞金(James E. Crowe Jr)博士稱，學術界的研究人員開發出一種對動物有效的原型藥物或疫苗之後，常常會與“生物科技死亡谷”不期而遇，沒有製藥公司願意幫助他們越過終點。

The Ebola vaccine on which Dr. Geisbert collaborated is made from another virus, V.S.V., for vesicular stomatitis virus, which causes a mouth disease in cattle but rarely infects people. It had already been used successfully in making other vaccines.

蓋斯伯特博士參與研發的埃博拉疫苗是利用另一種病毒——水皰性口炎病毒(VSV)製成的，這種病毒導致牛羣患上口部疾病，但很少感染人。該病毒已被成功用於製造其他疫苗。

The researchers altered V.S.V. by removing one of its genes — rendering the virus harmless — and inserting a gene from Ebola. The transplanted gene forces V.S.V. to sprout Ebola proteins on its surface. The proteins cannot cause illness, but they provoke an immune response that in monkeys, considered a good surrogate for humans, fought off the disease.

研究人員通過移除VSV的一個基因——使該病毒變得無害——並嵌入埃博拉病毒基因來改變VSV病毒。這種移植的基因迫使VSV在表面產生埃博拉病毒蛋白。這些蛋白不會導致疾病，但它們在猴子身上引發免疫反應，治癒這種疾病。猴子被認爲是代替人類測試藥品的好選擇。

The vaccine was actually produced in Winnipeg by the Public Health Agency of Canada. The Canadian government patented it, and 800 to 1,000 vials of the vaccine were produced. In 2010, it licensed the vaccine, known as VSV-EBOV, to NewLink Genetics, in Ames, Iowa.

該疫苗實際上是由加拿大公共衛生署(Public Health Agency of Canada)在溫尼伯研發的。加拿大政府擁有專利權，目前已經生產了800-1000劑疫苗。2010年，該政府爲愛荷華州埃姆斯的紐琳基因公司(NewLink Genetics)發放VSV-EBOV疫苗許可。

The Canadian government donated the existing vials to the World Health Organization, and safety tests of the vaccine in healthy volunteers have already begun.

加拿大政府將現有的疫苗捐贈給世界衛生組織，現在已經開始在健康的志願者身上進行疫苗安全測試。

NewLink's product is one of two leading vaccines being tested. The other, which uses a cold virus that infects chimpanzees, was developed by researchers at the National Institutes of Health and GlaxoSmithKline. The first tests of an earlier version of it, employing a different cold virus, began in 2003.

紐琳基因公司的產品是兩種正在進行測試的主要疫苗之一。另一種疫苗是由美國國立衛生研究院(National Institutes of Health/NIH)和葛蘭素史克公司(GlaxoSmithKline)的研究人員研發的，該疫苗使用了黑猩猩感冒病毒。相關人員從2003年開始首次對之前使用不同感冒病毒製成的疫苗進行測試。

Several other vaccine candidates, not as far along, are also in the pipeline and may be ready for safety testing next year. Once any drugs or treatments pass the safety tests they will be available for use in larger numbers of people, and health officials are grappling with whether they should be tested for efficacy in the traditional way, in which some people at risk are given placebos instead of the active drug.

其他幾種候選疫苗的進展沒有那麼快，但正在研製中，或許已經準備好於明年接受安全測試。一旦有藥物或治療方法通過安全測試，它們將可以用於廣大人羣，衛生官員正在考慮是否應該通過傳統方式對這些藥物進行療效測試——給一些可能被感染的人安慰劑，而不是活性藥物。

Governments and the military became interested in making vaccines against Ebola and a related virus, Marburg, during the 1990s after a Soviet defector said the Russians had found a way to weaponize Marburg and load it into warheads. Concerns intensified in 2001 after the Sept. 11 terrorist attacks and anthrax mailings.

20世紀90年代，在蘇聯叛徒稱俄羅斯人已經找到將馬爾堡病毒製成武器並將它裝入彈頭的方法後，各國政府及軍隊開始對製作抗埃博拉病毒及相關病毒——馬爾堡病毒的疫苗感興趣。2001年，在9·11恐怖襲擊事件及炭疽郵件事件發生之後，他們更加關注疫苗的製作。

"The National Institutes of Health came up with a program called Partnerships in Biodefense that partnered researchers like me with companies, usually small companies," Dr. Geisbert said.

蓋斯伯特博士說，“國立衛生研究院推出了一個叫作生物防禦合作(Partnerships in Biodefense)的計劃，推動像我這樣的研究人員與公司的合作，通常是些小公司。”

The government money led to major advances in the laboratory, Dr. Geisbert said, but was insufficient to cover the huge costs of human trials. Nor could the small companies that were involved in the early studies in animals afford to pay for human trials. No finished product came to market.

蓋斯伯特博士表示，政府的資助促使該實驗室取得重大進展，但這些資金不足以支付人體試驗所需要的鉅額費用。那些參與動物試驗早期研究的小公司也無法支付人體試驗的費用。目前還沒有成品上市。

Dr. Geisbert moved on, working on treatments for Ebola and another version of the V.S.V. vaccine. For the vaccine work, his main collaborator has been Dr. Heinz Feldmann, the chief of virology at the Rocky Mountain Laboratories in Hamilton, Mont., part of the National Institute of Allergy and Infectious Diseases.

蓋斯波特博士繼續研究埃博拉的治療方法，以及另一種VSV疫苗。在疫苗研製工作方面，他的主要合作伙伴是蒙大拿州哈密爾頓落基山實驗室(Rocky Mountain Laboratories)的首席病毒專家海因茨·費爾德曼(Heinz Feldmann)。落基山實驗室隸屬於美國國家過敏及傳染性疾病研究所(National Institute of Allergy and Infectious Diseases)。

The newer version of the vaccine uses a slightly different form of V.S.V., one that Dr. Geisbert said he thought might be less likely to cause side effects, and more likely to gain quick approval because it has already been used as the basis for an H.I.V. vaccine and is known to the Food and Drug Administration. But the new version, VesiculoVax, made by Profectus Biosciences in Baltimore, has not yet been tested in humans.

新版疫苗使用的VSV病毒稍有不同，蓋斯波特博士稱這種病毒引起副作用的可能性較小，可能很快就會獲得批准，因爲它已經被用於製造HIV疫苗，美國食品與藥品管理局(Food and Drug Administration)已經瞭解這種病毒。但巴爾的摩啓程生物科學公司(Profectus Biosciences)生產的新疫苗VesiculoVax還沒有進行人體測試。

The V.S.V. products are live vaccines, with replicating viruses that may cause a reaction. It is not clear what level of side effects will be considered acceptable.

VSV疫苗是活疫苗，不斷複製的病毒可能會引起反應。目前尚不清楚何種水平的副作用是被認爲可以接受的。

Chills and nausea are possible, Dr. Geisbert said, but he added, "Who cares, if you survive Ebola?"

蓋斯特博士表示，可能出現畏寒、噁心的反應，但他還表示，“如果能治癒埃博拉，誰還在乎這些？”