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. Author manuscript; available in PMC: 2017 Jun 29.
Published in final edited form as: N Engl J Med. 2015 Apr 1;374(17):1647–1660. doi: 10.1056/NEJMoa1502924

Figure 3. Glycoprotein Antibody Titers, According to Vaccine Dose, Study Site, and Assay.

Figure 3

Individual antibody titers were assessed at baseline and at 28 and 180 days after vaccination in 158 participants, according to study site and dose group. The vaccine dose (in PFU) is indicated for each site in Panels A through D; the shaded areas indicate negative titers. The numbers of samples tested are provided in Figure S4 in the Supplementary Appendix. Antibodies were measured on enzyme-linked immunosorbent assay (ELISA) against the homologous glycoprotein (GP) of the Zaire–Kikwit strain (ZEBOV, Panel A) or inactivated whole virions of the Zaire–Guéckédou strain (Panel B). Results are expressed as end-point titers (Panel A) or the geometric mean concentration of arbitrary ELISA units (AEU) per milliliter (Panel B). Neutralizing antibodies were detected with the use of rVSV pseudovirion neutralization assay assessing the 50% serum neutralization capacity (PsVNA50) complemented by homologous glycoprotein (Panel C) or with infectious ZEBOV isolate Mayinga (Panel D). Geometric mean titers and 95% confidence intervals are shown for each study site, dose group, and time point. The results of glycoprotein ELISA (Panel E) and pseudoneutralization (Panel F) at 28 days were expressed as the reciprocal of the highest dilution showing a positive result. The curves represent the distribution of individual antibody titers in each cohort. The dashed curves in Panel E indicate baseline titers.