Hamster Intranasal and Oral SARS-CoV-2 Vaccination

Male Golden Syrian hamsters (n=6) aged 6-8 weeks, were vaccinated according to the groupings in Figure 1B with a dose of 1x10⁹ infectious units (IU) diluted in 1xPBS in a total volume of 100 µL for intranasal vaccination (50 µL/nostril) and 1 mL total volume for oral gavage. Vaccinations occurred four weeks apart. Serum, nasal washes, and oral swabs were collected on day -1 (D1), day 27 (D27), and day 41 (D41) as described below. At D52, the animals were anesthetized by injecting 80 mg/kg ketamine and 5 mg/kg xylazine via intramuscular route in preparation for challenge. Animals were challenged with an appropriate dose via intranasal administration using a total volume of 100 μL per animal (50 μL/nostril), administered dropwise. SARS-CoV-2 delta variant (ATCC NR-56116 LOT#: 70047614) was dosed at 3.48x10³ TCID₅₀ per hamster and SARS-CoV-2 omicron variant (ATCC NR-56486 LOT#: 70049695 was dosed at 4.8x10⁴ TCID₅₀ per hamster as pre-determined in titration studies performed by Bioqual, Inc. Animals were monitored daily for any abnormal clinical observation and body weights were recorded. All in-life animal handling occurred at Bioqual, Inc (Rockville, MD).