Fig 4.

Dual vaccination with VRP-SUDV GP and VRP-EBOV GP protects cynomolgus macaques from EBOV i.m. challenge. NHPs were vaccinated with VRP expressing irrelevant antigen (n = 1) or VRPs expressing both SUDV GP and EBOV GP (n = 3). EBOV GP (A) or SUDV GP (B) specific serum antibody end titers were determined by ELISA at the indicated times postvaccination or challenge. Dotted line indicates assay limit of detection. Black and red arrows indicate time of EBOV challenge and SUDV back-challenge, respectively. (C) NHPs were challenged by i.m. injection of 1,000 PFU of EBOV 28 days postvaccination. (D) Surviving NHPs were then back challenged by i.m. injection of 1,000 PFU of SUDV 28 days post-EBOV challenge. **, P ≤ 0.01 (as determined by the Fisher exact test).