ACE2 and infection: Here, ACE2-Fc demonstrated significant protective effects at concentrations varying from 1.25 to 20 μg/ml, effectively preventing infection by pseudoviruses bearing Spike proteins from variants including Delta, BA.2, BA.2.75, BA.5, BF.7, BQ.1, XBB.1, JN.1, KP.2, and KP.3 (Fig. 2C).