ABSTRACT
Antigenic characterization of newly emerging SARS-CoV-2 variants is important to assess their immune escape and judge the need for future vaccine updates. As exposure histories for human sera become more and more complex, animal sera may provide an alternative for antigenic characterization of new variants. To bridge data obtained from animal sera with human sera, we here analyzed neutralizing antibody titers in human and hamster first infection sera in a highly controlled setting using the same live-virus neutralization assay performed in one laboratory. Using a Bayesian framework, we found that titer fold changes in hamster sera corresponded well to human sera and that hamster sera generally exhibited higher reactivity. Our results indicate that sera from infected hamsters are a good surrogate for the antigenic characterization of new variants.