Serostatus cutoff levels and fold increase to define seroresponse to recombinant vesicular stomatitis virus – Zaire Ebola virus envelope glycoprotein vaccine: An evidence-based analysis. Issue 31 (26th June 2020)

• Record Type: Journal Article
• Authors: Antonello, Joseph; Grant-Klein, Rebecca J.; Nichols, Rick; Kennedy, Stephen B.; Dubey, Sheri; Simon, Jakub K.
• Is Part Of: Vaccine. Volume 38:Issue 31(2020)
• Page Start: 4885
• Page End: 4891
• Publication Date: 2020-06-26
• Subjects: Ebola virus -- ELISA -- Seroresponse -- Vaccination; ELISA enzyme-linked immunosorbent assay -- FANG Filovirus Animal Nonclinical Group -- F-P Fisher's exact test 2-sided p-value -- IgG immunoglobulin G -- rGP recombinant glycoprotein -- RSD relative standard deviation -- rVSVΔG-ZEBOV-GP recombinant vesicular stomatitis virus – Zaire Ebola virus envelope glycoprotein -- SSCO serostatus cutoff -- VSV vesicular stomatitis virus -- Y-I Youden's index; Vaccines -- Periodicals; 615.372
• DOI: 10.1016/j.vaccine.2020.04.061
• Languages: English
• ISSNs: 0264-410X

Abstract

Highlights: Antibody response correlating with vaccination was used to define seroresponse. P-values from Fisher's exact test were used to compare definitions of seroresponse. Two-fold rise and SSCO of 200 EU/mL best differentiated vaccine/placebo recipients. Abstract: The recombinant vesicular stomatitis virus – Zaire Ebola virus envelope glycoprotein (rVSVΔG-ZEBOV-GP) vaccine is a live recombinant vesicular stomatitis virus (VSV) where the VSV G protein is replaced with ZEBOV-GP. To better understand the immune response after receiving the rVSVΔG-ZEBOV-GP vaccine, the current analyses evaluated different definitions of seroresponse that differentiate vaccine and placebo recipients enrolled in a placebo-controlled clinical trial (PREVAIL; NCT02344407) in which a subset of the study participants had elevated baseline titers. Alternative values for serostatus cutoff (SSCO; 200–500 EU/mL) and/or fold rise (two- to five-fold) were applied to compare their ability to distinguish between participants receiving rVSVΔG-ZEBOV-GP or placebo. The results indicate that an SSCO of 200 EU/mL can be used to define seropositivity at baseline (i.e. pre-vaccination). The use of dual criteria of the same SSCO (200 EU/mL) together with a two-fold rise in antibody level from baseline provided the definition of seroresponse that maximized the statistical significance between vaccine recipients and placebo recipients post-vaccination. Clinical trial registration: NCT02344407.