Scientists Race to Find Vaccine for Ebola, Marbug

Scientists have developed vaccines that protect against the deadly Ebola and Marburg viruses. They hope to test the vaccines — successful in experiments with monkeys — on humans in two to three years. The viruses are at the top of experts' list of bioterrorism threats.

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Scientists say new vaccines could protect against two deadly viruses, Ebola and Marburg. It's hoped they can protect people from an outbreak or from terrorism. NPR's Richard Knox reports.

RICHARD KNOX reporting:

Ebola and Marburg are among the baddest viruses out there. Eighty to 90 percent of infected people die. For years, scientists have worked on vaccines with limited success. Now one group has hit a scientific home run. It's in the journal Nature Medicine. Researchers took an animal virus called VSV, for vesicular stomatitis virus. They inserted some genes from either Ebola or Marburg. They injected these live but disabled viruses into monkeys. Then, four weeks later, they gave the animals super-lethal doses of Ebola or Marburg. Steven Jones is with Canada's Public Health Agency.

Mr. STEVEN JONES (Canada's Public Health Agency): Not only did the animals survive, but the growth of Ebola and Marburg in the bodies of the monkeys were completely suppressed. We couldn't find live virus, and we couldn't find the virus genes using the most sensitive detection tests that we have.

KNOX: The researchers couldn't detect any harmful effects from the vaccine, either. Dr. Thomas Geisbert did the monkey part of the experiment in the US Army's maximum security labs at Ft. Detrick, Maryland.

Dr. THOMAS GEISBERT (Researcher): This is the first vaccine system that has ever been shown to protect non-human primates against both viruses.

KNOX: The Ebola vaccine used genes from an especially lethal strain of the virus first identified in Zaire. The Marburg vaccine used a variant called Musoke from Kenya. Geisbert says that raises an urgent question.

Dr. GEISBERT: The studies that we're gonna start doing in June, we need to know, does this Marburg Musoke vaccine--will it, as a preventive vaccine, protect against the other strains of Marburg?

KNOX: Geisbert says the Marburg strain that has killed nearly 350 people this year in Angola may be the most lethal known. He says the vaccines are easy to use and produce immunity quickly. That would be important in the face of an outbreak.

Dr. GEISBERT: We know right now that we can get away with a single injection. That's another huge benefit. This isn't like a lot of vaccines where you have, you know, a series of two or three injections. This is a single injection.

KNOX: Getting any vaccine approved for humans is a complicated process. That's especially true for a vaccine against an exotic and deadly disease. It's not like testing a vaccine for flu or whooping cough. But Jones, the Canadian researcher, says if more animal studies go well, the Ebola and Marburg vaccines might be ready for human trials in a couple of years. Jones says new money for bioterrorism research is accelerating the work.

Mr. JONES: Unfortunately, these diseases are extremely good bioterrorist agents, and there's no question that the big push to develop vaccines is a result of the fact that it's well known now that the former Soviet Union had a large weapon of mass destruction program based around Marburg use.

KNOX: And the Aum Shinrikyo terrorists who unleashed nerve gas in the Tokyo subway 10 years ago reportedly tried to get their hands on Ebola virus during an outbreak in the Congo.

Mr. JONES: So we know that it's not just feasible, since the Russians tried it, but also that terrorists have at least considered doing it.

KNOX: But Daniel Bausch of Tulane University says the most urgent need is to make a difference in the Ebola and Marburg outbreaks occurring on an almost yearly basis in Africa. Health workers now can do nothing but quarantine infected people to prevent the disease from spreading. Bausch says it's not surprising that makes people run and hide.

Mr. DANIEL BAUSCH (Tulane University): We need to find the tools to flip that, to have them want to be counted, want to be admitted to a ward, and if you have a vaccine, then that changes the whole thing.

KNOX: Until health workers have something positive to offer, Bausch expects to see more fear and hostility, which only help to spread the disease. Richard Knox, NPR News.

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