A U.S. physician exposed to Ebola virus received an investigational vaccine afterward and didn’t contract the disease, but the vaccine’s effectiveness remains unknown, according to report published online March 5 in JAMA.
The vaccine, VSV[Delta]G-ZEBOV, is based on a vesicular stomatitis virus with the glycoprotein gene replaced by a Zaire Ebola glycoprotein gene.
The physician received the vaccine slightly less than 2 days after Ebola exposure. After 12 hours, symptoms appeared that are associated with vesicular stomatitis virus. Those dissipated after 3-4 days, noted Dr. Lilin Lai of Emory University, Atlanta, and her colleagues.
No Ebola symptoms were detected, but the patient tested positive for Ebola virus glycoprotein-specific antibodies and T cells, which was an intended effect of the vaccine.
A single case report cannot provide a definitive answer to the effectiveness of VSV[Delta]G-ZEBOV, noted Thomas W. Geisbert, Ph.D. of the Galveston National Laboratory, University of Texas Medical Branch, in a related editorial. However, “this incident serves as an example of how important it is to have safe and effective countermeasures available in sufficient quantities that can be rapidly deployed for emergency use for both medical workers and affected populations.”
Find the full study and editorial in JAMA: (doi: 10.1001/jama.2015.1995) and (doi: 10.1001/jama.2015.2057).