ACE2 and infection: While infections involving XBB were increasing due to its improved antibody evasion (16, 25, 89, –, 91), XBB.1.5 quickly dominated over XBB and BQ.1.1 due to its improved ACE2 affinity over XBB (27, –, 29) and improved immune escape compared to BQ.1.1 (92, –, 94).