More research on binding specificity of both animal and human 9-O-Ac-Sia-binding β1CoVs to the internal part of the receptor in combination with analysis of 9-O-Ac-Sia-containing glycan structures expressed on host tissues and analysis of changes in the viral S1A proteins could reveal which part of 9-O-Ac-Sia-containing glycans determines host/tissue tropism of β1CoVs and changes in the viral S1A proteins associated with host/tissue tropism.