Distinct sensitivities to SARS-CoV-2 variants in vaccinated humans and mice

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 2019 has led to the development of a large number of vaccines, several of which are now approved for use in humans. Understanding vaccine-elicited antibody responses against emerging SARS-CoV-2 variants of concern (VOC) in real time is key to inform public health policies. Serum neutralizing antibody titers are the current best correlate of protection from SARS-CoV-2 challenge in non-human primates and a key metric to understand immune evasion of VOC. We report that vaccinated BALB/c mice do not recapitulate faithfully the breadth and potency of neutralizing antibody responses against VOC, as compared to non-human primates or humans, suggesting caution should be exercised when interpreting data for this animal model. ### Competing Interest Statement A.C.W., N.P.K., and D.V. are named as inventors on patent applications filed by the University of Washington based on the RBD-NP presented in this paper. N.P.K. is a co-founder, shareholder, paid consultant, and chair of the scientific advisory board of Icosavax, Inc. and the King lab has received an unrelated sponsored research agreement from Pfizer. D.V. has received an unrelated sponsored research agreement from Vir Biotechnology, Inc. M.S.D. is a consultant for Inbios, Vir Biotechnology, and Carnival Corporation, and on the Scientific Advisory Boards of Moderna and Immunome. The Diamond laboratory has received unrelated funding support in sponsored research agreements from Vir Biotechnology, Kaleido, and Emergent BioSolutions and past support from Moderna not related to these studies. K.W., A.C., and D.K.E are employees of Moderna and hold stock/stock options in the company. D.H.F. has equity interest in HDT Bio.