PMID: 35266815 / doi: 10.1128/mbio.00099-22

Kappa, Delta, or B.1.618 spike uses human angiotensin-converting enzyme 2 (ACE2) with no or slightly increased efficiency, while it gains a significantly increased binding affinity with mouse, marmoset, and koala ACE2 orthologs, which exhibit limited binding with wild-type (WT) spike. Collectively, this study revealed that enhanced human and mouse ASE receptor engagement, increased spike cleavage, and reduced sensitivity to neutralization antibodies of Kapa, Delta and B.1.618 may contribute to the rapid spread of these variants.