“… 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 Consistent with this explanation, it also is clear that VSV vectors encoding Spike immunogens are immunogenic by other vaccination routes if they are designed to use infection pathways that are independent of ACE2. 27 , 50 , 94 , 96 , 97 , 98 , 99 Our initial hamster study using alternative routes assessed two mucosal vaccination methods. The high volume IN/OM combination was used initially to enable infection across multiple mucosal surfaces in the upper respiratory tract ( Figure 5 a), whereas another group was vaccinated by applying virus only to OM surfaces because data were emerging on ACE2 abundance and the susceptibility of cells to SAR-CoV-2 infection in the oral cavity.…”