Characterization of the SARS-CoV-2 BA.5.5 and BQ.1.1 Omicron variants in mice and hamsters

• DOI: 10.1128/jvi.00628-23
• Publication Date: 2023-09-07T13:01:46Z
• Authors: James Brett Case; Suzanne M. Scheaffer; Tamarand L. Darling; Traci L. Bricker; Lucas J. Adams; Houda H. Harastani; Reed Trende; Shilpa Sanapala; Daved H. Fremont; Adrianus C. M. Boon; Michael S. Diamond
• Keywords: Mesocricetus; Respiratory tract

The continued evolution and emergence of novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants have resulted in challenges to vaccine antibody efficacy. each new variant necessitates the need re-evaluate refine animal models used for countermeasure testing. Here, we tested a recently circulating SARS-CoV-2 Omicron lineage variant, BQ.1.1, multiple rodent including K18-human ACE2 (hACE2) transgenic, C57BL/6J, 129S2 mice, Syrian golden hamsters. In contrast previously dominant BA.5.5 inoculation K18-hACE2 mice with BQ.1.1 substantial weight loss, characteristic seen pre-Omicron variants. also replicated higher levels lungs caused greater lung pathology than variant. However, C57BL/6J hamsters, did not cause increased tract infection or disease compared animals administered BA.5.5. Moreover, rates direct contact airborne transmission hamsters were significantly different after infections. Taken together, these data suggest that has virulence species express hACE2, possibly due acquisition unique spike mutations relative earlier IMPORTANCE As continues evolve, there is rapidly assess efficacy vaccines antiviral therapeutics against newly emergent To do so, commonly must be re-evaluated. determined pathogenicity transgenic expressing human (hACE2), two strains conventional laboratory While similar viral burden clinical tested, increases detected hACE2-expressing which corresponded pro-inflammatory cytokines pathology. our highlight important differences closely related provide foundation evaluating countermeasures.