Fig. 6. Prophylaxis of human anti-hACE2 antibodies for SARS-CoV-2 infection in mice.

a, Anti-hACE2 mAb levels following subcutaneous injection of 250 μg (equivalent to approximately 12.5 mg kg⁻¹) of anti-hACE2 antibodies (05B04, 05H02, 2G7A1 and 05B04LC/05D06HC) into each of five hACE2 knock-in mice (B6.129S2(Cg)-Ace2tm1(ACE2)Dwnt/J) on day 0. Serum dilutions (0.5 μl, 0.1 μl or 0.02 μl) of the sera collected on the indicated days or mAb standards were mixed with hACE2 (1–740aa)-NanoLuc fusion protein and captured by Protein G beads (Extended Data Fig. 4). Dashed red line indicates IC₅₀ for inhibition of SARS-CoV-2 pseudotyped virus infection. b,c, Human ACE2 knock-in mice (B6.129S2(Cg)-Ace2tm1(ACE2)Dwnt/J) (n = 5) were injected with 250 μg (equivalent to 12.5 mg kg⁻¹) of the anti-hACE2 antibodies (05B04, 05H02, 2G7A1 or 05B04LC/05D06HC): at 2 days after antibody injection mice were challenged intranasally with SARS-CoV-2, USA_WA/2020 P3, 2 × 10⁵ PFU per mouse (virus titres measured on Vero E6 cells) (b); 3 days later, mouse lungs were collected and RNA extracted, and the number of viral genomes per µg of total lung RNA was measured using qRT–PCR (c).

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