PHV01 prevents death and disease following MARV challenge. In Experiment #1 (A,B), guinea pigs (n = 6) were vaccinated with rVSVΔG-MARV P3 and PHV01 MVS at one of three different dose levels (high, medium, or low). In Experiment #2 (C,D), guinea pigs (n = 6) were vaccinated with PHV01 FDS at one of two different dose levels (high or medium) or with PHV01 MVS at the high dose level. Control animals (n = 6) in both experiments received saline. Twenty-eight days after vaccination, animals were challenged with a lethal dose of guinea-pig-adapted MARV and monitored for survival (A,C) and weight change (B,D). Survival curves for all vaccinated groups were significantly different from the control groups (Log-Rank with Bonferroni correction; *, p ≤ 0.05; **, p ≤ 0.01). Vaccinated animals that did not survive infection are indicated on the weight loss curves by their respective animal numbers: 9, rVSVΔG-MARV P3 medium dose; 16, P3 low dose; 31 and 32, PHV01 MVS low dose; 60, PHV01 FDS medium dose.