Experimental Ebola Vaccine Appears Successful in At Least One Case

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THURSDAY, March 5, 2015 (HealthDay News) -- An experimental Ebola vaccine may have prevented the disease in a doctor who was at high risk of infection, according to a new report.

The report comes on the heels of news from the World Health Organization that trials of the vaccine, called VSV-EBOV, will begin this weekend in the West African nation of Guinea.

"If a vaccine is found effective, it will be the first preventive tool against Ebola in history," WHO Director-General Dr. Margaret Chan said in an agency statement.

In the new case report, researchers led by Dr. Mark Mulligan, of Emory University in Atlanta, said the 44-year-old doctor was stuck by a needle last September at an Ebola clinic in Sierra Leone. He agreed to receive the experimental vaccine after he was exposed.

The doctor's body fought off the virus with a strong, targeted reaction -- suggesting that VSV-EBOV may be helpful in preventing infection. However, the researchers said that it's still too early to know if the vaccine is actually safe and effective.

The doctor returned to the United States for treatment and follow-up. About 14 hours after receiving the vaccine, the doctor developed symptoms, such as fever, nausea and muscle aches. He continued having symptoms the next day, but on days three through five after receiving the vaccine, his symptoms improved, and he was symptom-free by day seven, Mulligan's team said.

The findings are published March 5 in the Journal of the American Medical Association.

"Future decision-making about using this experimental vaccine for postexposure vaccination will need to balance the risks of harm from the vaccine or possible Ebola infection (both were unknowns at the time of the patient's exposure) against the possible benefit of vaccination (also unknown at the time of the patient's treatment)," the study authors wrote.

Thomas Geisbert is professor of microbiology and immunology at the University of Texas Medical Branch at Galveston, and also the author of an editorial accompanying the new study.

Speaking with HealthDay, he said that "the article reinforces the need for fast-acting single-injection preventive vaccines to control and manage outbreaks."

Geisbert said that the VSV-EBOV vaccine has proven effective against Ebola in monkey studies when given shortly after exposure to the virus.

If proven safe and effective in humans, the single-dose shot "would have great utility for things like vaccinating health care workers and first responders, say, right before you put them on an airplane to go into the hot zone."

Or it could be given to "high-risk" people living in an outbreak area, Geisbert said.

"Again, in that case you don't have time for a vaccine that requires multiple injections or a long time to work," he explained. "This is where the VSV-EBOV vaccine is head and shoulders above all other vaccines to date."

More information

For more about the Ebola virus, visit the U.S. Centers for Disease Control and Prevention.