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.
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.
“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.
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.
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.
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 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.
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.
Chills and nausea are possible, Dr. Geisbert said, but he added, “Who cares, if you survive Ebola?”
Most vaccines are given to prevent disease before people are exposed to it, and the plan is to use Ebola vaccines that way. But the V.S.V. vaccines have also been shown to protect monkeys even after the animals have been exposed to a heavy dose of Ebola — if given soon after exposure.
Researchers hope that they will work that way for people, too. If they do, health workers and family members who have been in contact with a patient might be protected, instead of having to spend 21 days of dread, waiting to see if they get sick.
Dr. Geisbert spends much of his time working with Ebola and other deadly viruses in a Biosafety Level 4 laboratory at the Galveston National Laboratory, where the researchers wear spacesuits that each come with an independent air supply, and visiting journalists are required not to report which floor the labs are on.
This month, one of his tasks is to test the Profectus vaccine and an experimental treatment against the Ebola strain that is causing the current epidemic. The virus is from a species called Ebola Zaire, against which the products have already been shown to work. But different strains within a species can vary genetically by 2 percent to 7 percent, Dr. Geisbert said.
Most of the time, those small variations do not matter, and a drug or treatment that works against one strain will work against all. But once in a while, the difference matters. (NY Times)