ACE2 and infection: In a human ACE2 transgenic mouse model6, intraperitoneal administrations of R1-32 at 4 mg kg−1 and 20 mg kg−1 at 1 h post intranasal inoculation of 5 × 105 plaque-forming units (p.f.u.)SARS-CoV-2 wild-type virus were able to significantly reduce viral load in lung, 3 d post infection, compared with the control group (Fig. 1d).