Abstract
Persistence of immune responses induced by Ebola virus vaccines.
Highlights
The recent devastating outbreak of Ebola virus disease led to the accelerated development of multiple candidate vaccines against this virus, with at least eight entering clinical trials in 2014–16.1 Direct evidence of 100% effectiveness against disease has been demonstrated for VSV-EBOV, a vaccine based on a replicating vesicular stomatitis virus genetically modified to express Ebola virus glycoprotein.[2]. This vaccine has been granted Breakthrough Therapy Designation status by the US Food and Drug Administration and PRIME status by the European Medicines Agency, and its single-dose regimen and proof of effectiveness from 10 days postimmunisation make it an attractive candidate for use in a responsive campaign. Where does this leave the other potential vaccines, and what additional information is required to inform their use? Many of these vaccines are based on a nonreplicating adenoviral vector modified to express the Ebola glycoprotein (eg, adenovirus 5 (Ad5-ZEBOV),[3] chimpanzee adenovirus 3 (Chad3),[4] or adenovirus 26 (AD26-ZEBOV),[5] which could potentially be used in heterologous prime/boost schedules together with a vaccine that uses an alternative viral vector bearing the same or similar Ebola glycoproteins
Most published clinical data on these vaccines are from phase 1 studies conducted in Europe, North America, and China, numerous studies are ongoing or recently completed in sub-Saharan Africa,[1] including a phase 2 Ad5-ZEBOV study conducted in Sierra Leone, recently published in the Lancet.[3]
Interpretation of these data is complicated by interlaboratory variability in the assays used in different clinical trials, the lack of a known immunological correlate of protection, and whether a correlate identified for the one vaccine with evidence of effectiveness (VSV-EBOV, using a replicating viral vector) would apply to immunity induced by a vaccine such as Ad5-ZEBOV that uses a non-replicating viral vector
Summary
Li and colleagues’ study suggests that 6 months after a dose of Ad5-ZEBOV administered to healthy adults in China, Ebola-glycoprotein-specific IgG concentrations were less than half that of their postimmunisation peak. Persistence of immune responses induced by Ebola virus vaccines
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
