Emergency post-exposure vaccination against Ebola described in case report

Woodruff Health Sciences Center | March 5, 2015

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Vincent Dollard
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A physician who experienced an accidental needlestick in an Ebola treatment unit in Sierra Leone, and then treated with an experimental Ebola vaccine, is described in a case report published in the Journal of the American Medical Association.

The exposed individual was vaccinated 43 hours after the needlestick and was transported by jet to the National Institutes of Health Special Clinical Studies Unit in Maryland.

"Until there is an effective preventive vaccine against Ebola virus, having a treatment or vaccine to offer an exposed healthcare worker is an important goal," says the JAMA paper's corresponding author, Mark Mulligan, MD, executive director of the Hope Clinic of the Emory Vaccine Center.

"We can't know the safety or the protection provided by post-exposure vaccination based on this single patient report, but at a time when all available information about Ebola vaccines must be garnered, the clinical and immunological data presented are informative. The vaccine produced a strong early immune response."

The co-first authors of the JAMA paper are Lilin Lai, MD from Emory's Department of Medicine and Richard Davey, MD, from the NIH Clinical Studies Unit.

A clinical trial testing the ability of this experimental vaccine to prevent Ebola disease recently began in West Africa. The vaccine was developed by Public Health Agency Canada and NewLink Genetics, Inc and has been licensed to Merck. It is a replicating attenuated vesicular stomatitis virus, , called VSVΔG-ZEBOV, with its surface glycoprotein gene replaced by the Zaire Ebola virus glycoprotein gene.

The 44-year old physician from the United States was caring for patients in an Ebola treatment unit in Sierra Leone when he experienced an accidental needle stick on September 26, 2014. Given the concern about a significant risk of potentially lethal Ebola infection, the physician consented to post-exposure vaccination. Forty-three hours after exposure, he boarded a jet for medical evacuation to the United States and received the vaccine.

Starting 12 hours after vaccination, the physician experienced fever and other moderate to severe symptoms such as nausea, chills and muscle aches, and these symptoms diminished over the next three to four days. 

"We don't know if that level of symptoms represents a typical experience with this vaccine," Mulligan says. "We can only describe what happened in this one patient."

Blood PCR (polymerase chain reaction) tests detected the vescular stomatitis virus nucleoprotein gene and the Ebola virus glycoprotein gene, both included in the vaccine, but not the Ebola virus nucleoprotein gene, not in the vaccine. Antibodies and T cells were detected against the Ebola virus glycoprotein but not other Ebola proteins.

This indicates that the physician's immune system was responding to the components of the vaccine, not to live Ebola virus, Mulligan says.  There was no evidence of infection with the Ebola virus, and the most likely explanation was that he did not become infected with Ebola as a result of his needlestick exposure, he says.

The research was supported by the Georgia Research Alliance, the National Center for Advancing Translational Sciences (UL1TR000454), the National Institute of Allergy and Infectious Diseases (T32AI074492 and intramural research program).