Fig. 4. WRAIR monoclonal antibodies offer low-dose prophylactic protection in the K18-hACE2 mouse model.
a–c, Antibodies were infused intravenously at a single high dose of 400 µg (20 mg per kg body weight; a) or low doses of 2 µg (1 mg per kg body weight) and lower (b and c) into groups of mice (n = 15 per group). Mice were challenged intranasally 24 h later with 1.25 × 104 viral particles (1.25 × 104 PFUs) of SARS-CoV-2 (WA1/2020). SARS-CoV-2 viral loads in lung tissue were measured 2 d after challenge in a subset of animals (n = 5 per group) by plaque assay. Bars indicate the mean group value with standard deviation. The remaining mice (n = 10 per group) were assessed daily for weight and clinical symptoms. c, Assessment of Fc effector functions on animal protection for NTD and RBD antibodies. Wild-type and LALA-PG versions of mAb WRAIR-2039 (NTD) and WRAIR-2123 (RBD) were compared at 20 µg (1 mg per kg body weight). For weight loss and viral load in lungs, asterisks indicate significance compared to the ZIKV_MZ4 mAb isotype control group, by one-way analysis of variance (ANOVA) with Dunnett’s multiple-comparisons test. Survival curves were compared individually to the isotype control using a Mantel–Cox log-rank test. For all tests, ****P < 0.0001, ***P < 0.001, **P < 0.01, *P < 0.5; NS, not significant (P > 0.5).