Survival and Plasma Viraemia for Rhesus Monkeys Given Post-Exposure Treatment for ZEBOV Infection
(A) Kaplan-Meier survival curves for animals treated with ∼2 ×107 pfu of VSVΔG/ZEBOVGP (subjects 1 to 8, solid line) or VSV control vectors (subjects c1 and c2, dotted line) 20–30 min after i.m. challenge with 1,000 pfu of ZEBOV.
(B) Plasma viraemia of animals treated with VSVΔG/ZEBOVGP or VSV control vectors 20–30 min after i.m. challenge with 1,000 pfu of ZEBOV. Viraemia was determined by plaque assay at indicated time points. The asterisk indicates that on day 8 post-challenge viraemia levels were only determined for the control animals (subjects c1 and c2). Plasma viraemia levels at day 6 post-ZEBOV challenge could be separated into three different groups. Control animals, which received VSV control vectors (black square), developed high plasma viraemias (>6 log10 pfu/ml). Animals treated with VSVΔG/ZEBOVGP, which developed fulminant EBOV HF and succumbed to ZEBOV challenge (orange square), developed moderate plasma viraemias (∼4–6 log10 pfu/ml), while animals treated with VSVΔG/ZEBOVGP, which survived (green square), had low plasma viraemias (≤1.4 log10 pfu/ml). Subject 6 did not develop fulminant disease consistent with EBOV HF and succumbed on day 18 from a secondary bacterial infection.