Fig. 3: MD65 Ab-mediated prophylactic and post-exposure protection against SARS-CoV-2-infected K18-hACE2 mice.

Prophylactic (a–c) or post-exposure (d–f) in vivo protection experiments. Animals were intranasal infected with 200 PFU of SARS-CoV-2 BavPat1/2020 strain and IP administered with 1 mg/mouse of MD65 Ab at the indicated time points and 4 days later, for a second time. a Schematic description of the experimental design of the prophylactic treatment. b Body weight profiles. c Kaplan–Meyer surviving curves. Curves describe mice treated with the MD65 antibody (red line), naïve untreated and un-infected animals (black line), animals administered with PBS (gray line) or the isotype control irrelevant-Ab (anti-ricin MH75; green line) at the same time point as the MD65 treatment. d Schematic description of the experimental design of the post-exposure treatment. e Body weight profiles. f Kaplan–Meyer surviving curves. Curves describe mice treated with the MD65 antibody at various time points post-infection, as indicated by different colors in the legend within the panel and by the similarly colored arrows in panel d. Control animals (gray curves) were administered with PBS at day 2 and day 6 after infection. Body weight change is displayed as the percentage of initial weight. Only data of the first 7 days are presented in the control groups exhibiting significant mortality. In case of the mice treated 4 dpi (panel e), the weight of the surviving animals is indicated by hollow circles and dashed line. Data represent means ± SEM. The n numbers indicate the number of animals within each experimental group; when n > 5, the results were combined from several experiments in which each group included at least four animals.