Fig. 5: SARS-CoV-2 transmission by directional airflow in golden hamsters

Six-to-twelve-week-old female (n = 3) and male (n = 3) Syrian golden hamsters (Mesocricetus auratus) were 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, by a low volume inoculum (20 µL) via the intranasal route of administration to serve as the donor animals. One day (24 h) after infection, donor animals were removed from the original cage and paired with a sex-matched naïve sentinel animal for co-housing in respiratory transmission unit with a separation of 9 cm between the two animals with directional airflow (air flow from donor to naïve sentinel). Oropharyngeal swab samples were obtained from donor (A) and recipient hamsters (B) on days 0, 1, 2, 4, and 6 after inoculation (A) or after directional airflow transmission unit housing exposure (B) and infectious titers at the indicated day after infection/exposure for each individual hamster are indicated by the bar heights. Bars in A and B are ordered to depict animal pairings in a discrete respiratory transmission unit. C The overall percent transmission is shown, indicating the number of naïve, exposed hamsters in each group that had at least one oropharyngeal swab above the limit of detection (LOD). The LOD is indicated by a dotted horizontal line. Three independent experiments were carried out, and the data were combined. (total n = 6).