ACE2 and infection: The predominance of the Omicron variant facilitatesthe recombinationof existing lineages, leading to the emergence of novel lineages.Lineage BA.2 and BA.4/BA.5 have a stronger proximity to ACE2 thanBA.1.23,26 The sublineage BA.2.75 originated from BA.2has enhanced infection ability and binding affinity for ACE2 in comparisonwith BA.2 and BA.5 lineages.27 The N460Kand G339H mutations of BA.2.75 were found to increase the abilityof BA.2.75 to bind to ACE2.