In hamsters treated two-weeks prior to PICV challenge, DEF201 significantly reduced mortality (50% survival) and extended the time of death in the animals that succumbed ( Figure 3C ). In contrast, uniform lethality was seen with animals that received the rAd EV and placebo treatments. Of the 5 surviving animals pre-treated with DEF201, one was anorexic at the conclusion of the study on day 28 post-infection. This was reflected by a 27% weight loss compared to the animals starting weight. It is possible that this hamster, which appeared ill and lethargic, was not able to completely prevent the infection. It was unclear whether it would have ultimately recovered if the observation period had been extended.