SARS‐CoV‐2 Omicron (B.1.1.529) infection in rhesus macaques, hamsters, and BALB/c mice with severe lung histopathological damage

Abstract

AbstractSince the first SARS‐CoV‐2 outbreak in late 2019, the SARS‐CoV‐2 genome has harbored multiple mutations, especially spike protein mutations. The currently fast‐spreading Omicron variant that manifests without symptoms or with upper respiratory diseases has been recognized as a serious global public health problem. However, its pathological mechanism is largely unknown. In this work, rhesus macaques, hamsters, and BALB/C mice were employed as animal models to explore the pathogenesis of Omicron (B.1.1.529). Notably, Omicron (B.1.1.529) infected the nasal turbinates, tracheae, bronchi, and lungs of hamsters and BALB/C mice with higher viral loads than in those of rhesus macaques. Severe histopathological damage and inflammatory responses were observed in the lungs of Omicron (B.1.1.529)‐infected animals. In addition, viral replication was found in multiple extrapulmonary organs. Results indicated that hamsters and BALB/c mice are potential animal models for studies on the development of drugs/vaccines and therapies for Omicron (B.1.1.529).