Experimental Ebola Vaccine

Last September, a 44-year-old physician from the United States suffered a needle stick while caring for Ebola patients in a Sierra Leone treatment unit.

Within 43 hours, the doctor was injected with the experimental VSVΔG-ZEBOV vaccine.

The doctor had a fever and other symptoms from the vaccine for several days, but he never developed Ebola.

Nonetheless, the vaccine stimulated a strong response from his immune system. The doctor is now considered immune from the deadly virus.


The treatment is at the center of a new study published today in The Journal of the American Medical Association.

While researchers have yet to determine the safety and efficacy of the VSVΔG-ZEBOV vaccine, they say this patient’s experience shows promise for the future of Ebola treatment research.

The vaccine is now in a clinical trial for the prevention of Ebola in West Africa.

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The Promise of a Vaccine

According to the Centers for Disease Control and Prevention, no FDA-approved vaccines or medicines to treat Ebola currently exist.

Patients typically rely on basic interventions that include receiving intravenous fluids and balancing electrolytes, maintaining oxygen status and blood pressure, and treating other infections should they occur.

Experimental treatments such as the VSVΔG-ZEBOV vaccine are in the works, but their benefits and risks are still unknown.

This recently reported case study is very encouraging, but it does generate as many questions as answers.
Dr. Lee Norman, The University of Kansas Hospital

“This recently reported case study is very encouraging, but it does generate as many questions as answers,” said Lee Norman, M.D., chief medical officer at The University of Kansas Hospital, who was not involved in the study. “For example, would the patient have gotten the infection or not, and were the symptoms immunization-related only? That the immune response occurred like it did suggest an immune response to the vaccine.”

Norman calls this particular immune response “very exciting.”

Researchers find reason to be optimistic as well.

“Neither the safety nor the efficacy of the VSVΔG-ZEBOV vaccine for post-exposure protection can be learned from this single case, but the clinical and laboratory parameters are informative at a time when there is a need to garner all information available on Ebola vaccines,” said Mark J. Mulligan, M.D., of the Hope Clinic of the Emory Vaccine Center, Emory University, Atlanta, in a press release.

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Finding Solutions for Ebola

Before the height of the worldwide Ebola panic in 2014, the disease was largely ignored in the United States and other countries. And until then, there had been little demand for treatment, says the author of an accompanying study editorial.

“Historically, there has been a small global market for developing an Ebola virus vaccine and there was no financial interest for large pharmaceutical companies to become involved,” said Thomas W. Geisbert, Ph.D., of the University of Texas Medical Branch in Galveston, in a press release. “The current epidemic has spurred substantial scientific activity to develop vaccines.”

The fervor has settled down a bit, but studies such as this one could renew interest in finding treatments to eradicate the disease.

We must remain vigilant and keep this top-of-mind and be prepared to respond.
Dr. Lee Norman, The University of Kansas Hospital

In addition, the crisis isn’t over in certain parts of the world. The World Health Organization’s most recent Ebola Situation Report shows 99 new confirmed cases of the disease as of Feb. 22.

“The number of new Ebola cases in West Africa has slowed dramatically, but as long as there are new cases emerging, as we see in Sierra Leone, the global threat remains,” said Norman. “We must remain vigilant and keep this top-of-mind and be prepared to respond.”

Even though this discovery represents a potentially significant breakthrough, the treatment itself is only one part of a much larger conundrum. Getting the VSVΔG-ZEBOV vaccine and other Ebola treatments to those in need is a complicated process.

“The logistics of getting post-exposure vaccination to many areas of these West African nations remains a daunting task,” Norman said. “Vaccine storage, refrigeration, transportation, administration, funding, and cultural impediments will remain as huge challenges.”

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