Fig. 2. SARS-CoV-2 infection causes anosmia in K18-hACE2 mice.

Male and female mice were treated with PBS (uninfected) or 10⁵ PFU SARS-CoV-2 intranasally. a,d. Schematic showing social scent discrimination tests. b,e. Weights were recorded daily. c. Each male mouse was allowed 5 minutes in the cage with male and female scent (bedding from male or female cages) placed at two corners of the cage. The time that male mice spent sniffing male or female scent was recorded. Data were analyzed by 2-way ANOVA. f. Female mice were exposed to their own bedding (‘familiar’) or bedding from another cage (‘novel’). The time that female mice spent exploring each bedding was recorded. Data were analyzed by 2-way ANOVA. In some experiments, mice were pretreated with undiluted convalescent plasma (results on right of vertical line (c,f)). g-i. Buried food test (schematic shown in g). Food was buried under the bedding and each mouse was allowed 4 minutes in the cage to search for the food. h. The dotted line denotes the time limit of 4 minutes. Data were analyzed by 2-tailed Mann-Whitney U-tests. i. The percentage of mice that found the buried food within 4 minutes is shown. Data were analyzed by χ² Fisher’s exact test. In some experiments, mice were pretreated with undiluted convalescent plasma (denoted by blue bars in h,i). Male mice: uninfected: n=15 mice; infected: n=10 mice. Female mice: uninfected and infected: n=8 mice each; infected/CP-treated: n=7 mice. analyzed in 4 independent experiments. (b,c,e,f,h,i) Data are shown as mean±SEM. Preferences indices for the social scent discrimination assays are shown in Extended Data 5.