Study design and total IgG ELISA titers post vaccination.

(A) Vaccination and SARS-CoV-2 challenge study design. Syrian golden hamsters were given 5 μg of Pfizer BNT162b2 mRNA vaccine or PBS via the intramuscular route once (n = 30 hamsters/group). Blood was collected for serology 3-weeks post-vaccination. Animals were either mock-challenged or challenged with the indicated SARS-CoV-2 variants. Morbidity was monitored daily as body weight changes and lungs, spleen and blood were collected at 5 days post infection (DPI). Figure created with Biorender.com (B) USA-WA1/2020 SARS-CoV-2 S-specific IgG ELISA titers in hamster sera 3-weeks post-vaccination. Pfizer-BNT162b2 vaccinated hamsters (n = 30) are presented in grey and unvaccinated controls (n = 30) are presented in white. Values under the Limit of Detection (10²) are set to 10 for representation purposes. (C) Microneutralization assays in hamster sera 3-weeks post- vaccination against USA-WA1/2020, Alpha, Beta, Delta and Mu variants. The assay was performed with 350 TCID₅₀ per well on VeroE6/TMPRSS2 in all cases.