Syrian hamsters were inoculated with Omicron through the intranasal (IN) or intratracheal (IT) route (group size N = 6). Shedding and virus titers in tissues at 5 DPE were compared. A. Viral load as measured by sgRNA in oropharyngeal swabs collected at 1–5 days post inoculation. Whisker-plots depicting median, min and max values, and individual values, N = 6. B. sgRNA in lungs and nasal turbinates. Whisker-plots depicting median, min and max values, and individual values. Kruskal-Wallis test, N = 6. C. Lung weights (lung : body ratio). Whisker-plots depicting median, min and max values, and individual values, Kruskal-Wallis test, N = 6. D. Gross pathology of lungs on IN (top) and IT (bottom) inoculated animals at 5 DPE (left), histopathology (HE, middle), and immunohistochemistry against SARS-COV-2 NP (IHC, 200x, right) E. Percentage of lungs affected. F. Quantitative analysis of the NP reactivity. Whisker-plots depicting median, min and max values, and individual values. Kruskal-Wallis test, N = 6. G. For each airborne transmission, cage air was sampled in 24h intervals. Measurement of each individual cage is shown for gRNA. black = IN, white = IT. P-values stated were significant (<0.05).