In contrast to infected littermate control animals, Ace2-/y mice were fully protected against infection with 5 × 105 TCID50 maVie16, maintained stable body weight (Figure 7B) and temperature (Figure 7C), and were protected from pneumonia development as indicated by lower lung weight (Figure 7D) and the absence of any lung pathology (Figure 7E). Here, ACE2 is linked to susceptibility to pneumonia measurement.