ACE2 and COVID-19: Following this, wild-type-specific ACE2 displacement activities declined similarly in both COVID-19-naive groups: at three months, activities had decreased to a median 97.9% (IQR 88.8–99.6) in PWH versus 98.8% (IQR 94.5–99.5) in controls (P = 0.8), while by 6 months, activities had decreased to a median 87% (IQR 67.5–98.1) in PWH versus 93.6% (IQR 81.5–97.8) in controls (P = 0.3), levels that were comparable or lower than after two-dose vaccination (all P < 0.1) (Figs. 2a and b).