VZVΔG-ZEBOV vaccine may be effective in preventing Ebola virus infection

1. In this report of a 44-year-old male exposed to Ebola virus through a needle stick in Sierra Leone, vaccination with an experimental vaccine (VZVDG-ZEBOV) was effective in preventing Ebola virus infection.

2. Laboratory analysis indicated an innate and adaptive immune response after administration of the VZVDG-ZEBOV vaccine.

Evidence Rating Level: 3 (Average)   

Study Rundown: A 44-year-old male physician from the United States sustained a needle stick injury through gloves that had been in contact with severely ill Ebola patients in Sierra Leone. He cleaned the area and the patient was prepared for medical evacuation to the US. The patient agreed to receive an experimental Ebola vaccine (VZVDG-ZEBOV), a replicating, attenuated, recombinant vesicular stomatitis virus with a glycoprotein replaced by an Ebola virus glycoprotein. It can be used for vaccination in both preventative and postexposure settings. Prior to this case, the VZVDG-ZEBOV vaccine had been used in only one other human. This case report details the patient’s response to the vaccination and demonstrates the time course to symptomatic and laboratory resolution of the virus. It additionally highlights both the innate and adaptive immune responses activated by the vaccine. At 4 month follow up, the patient continues to be asymptomatic and is doing well.

Strengths of this study include the careful monitoring and recording of the clinical course of the patient and the fact that this is one of the first reports of a human receiving the VZVDG-ZEBOV Ebola vaccine. While the case report reveals promising results regarding the safety and efficacy of the VZVDG-ZEBOV vaccination, larger studies are needed to fully vet its potential.

Click to read the study, published today in JAMA

Click to read an accompanying editorial in JAMA

Relevant Reading: Management of accidental exposure to Ebola virus in the biosafety level 4 laboratory, Hamburg, Germany.

In-Depth [case report]: This study documents the experience of a 44-year-old American physician exposed to Ebola virus while working in Sierra Leone who received an experimental vaccine (VZVDG-ZEBOV) to prevent Ebola virus infection. He received the vaccine 43 hours after exposure. Twelve hours after vaccine administration, he developed nausea, myalgias, chills, and malaise. These symptoms resolved by day 7. Over the course of this time, he also had fevers (as high as 39.1 degrees Celsius) and mildly low oxygen saturations (94-96%). He also had leukopenia, thrombocytopenia, lymphopenia, and an elevated D-dimer. PCR studies were consistently negative for Ebola virus infection. Nine days after vaccine administration, he was discharged home to complete a 21-day isolation period. He then returned to work and was doing well four months later. Laboratory analysis throughout his course indicated both innate and adaptive immune responses in response to the VZVDG-ZEBOV vaccine, with a serum IgM against the Ebola virus glycoprotein detected on day 17 and a serum IgG initially detected on day 17 and an increased level detected on day 34. T cell activation was noted on day 2.

Image: PD

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