Fig. 3: SARS-CoV-2 infection of golden hamsters.

Six-to-twelve-week-old female and male golden hamsters (Mesocricetus auratus) were mock inoculated (black) or inoculated with 10⁴ TCID50 of each SARS-CoV-2 variant, D614G (gold), Alpha (dark blue), Gamma (teal), Delta (orange), Omicron BA.1 (light blue), and Omicron BA.2 (maroon) virus, using a low volume inoculum (20 µL) via the intranasal route of administration. A Animals were weighed daily up to 21 days post infection (dpi) (one experiments, n = 4). Circles indicate the mean ± s.e.m. infectious viral load (filled in shapes, left axis) and vRNA levels (empty shapes, right axis) were measured at 3 dpi in oropharyngeal swab samples (B), nasal turbinates (C), and lungs (D). Data were collected in a series of three experiments (n = 2 per group). Lines indicate means and error lines indicate s.d. Where statistics are indicated one-way ANOVA was carried out: *p ≤ 0.05, **p ≤ 0.01 *** p ≤ 0.001, **** p ≤ 0.0001 and the asterisk color indicates the comparator group with grey indicating a statistically significant difference compared to all the other groups individually, but excluding the mock-infected group. Heatmaps illustrating the cytokine transcript levels detected in SARS-CoV-2 D614G, Alpha, Gamma, Delta, Omicron BA.1, and Omicron BA.2 variant-infected hamster nasal turbinate (E) and lung (F) tissues.