SARS-CoV-2 disease severity and transmission efficiency is increased for airborne but not fomite exposure in Syrian hamsters

Abstract

Transmission of SARS-CoV-2 is driven by contact, fomite, and airborne transmission. The relative contribution of different transmission routes remains subject to debate. Here, we show Syrian hamsters are susceptible to SARS-CoV-2 infection through intranasal, aerosol and fomite exposure. Different routes of exposure presented with distinct disease manifestations. Intranasal and aerosol inoculation caused more severe respiratory pathology, higher virus loads and increased weight loss. Fomite exposure led to milder disease manifestation characterized by an anti-inflammatory immune state and delayed shedding pattern. Whereas the overall magnitude of respiratory virus shedding was not linked to disease severity, the onset of shedding was. Early shedding was linked to an increase in disease severity. Airborne transmission was more efficient than fomite transmission and dependent on the direction of the airflow. Carefully characterized of SARS-CoV-2 transmission models will be crucial to assess potential changes in transmission and pathogenic potential in the light of the ongoing SARS-CoV-2 evolution.

ChAdOx1 nCoV-19 (AZD1222) protects Syrian hamsters against SARS-CoV-2 B.1.351 and B.1.1.7

“…Upon necropsy, lungs from control animals showed gross lesions previously observed in hamsters inoculated with SARS-CoV-2 WA1 or a D614G isolate, with focal areas of hilar consolidation and hyperemia 4,5 . No gross lesions were observed in lung tissue obtained from any of the vaccinated animals (Figure 2a-d).…”

Sex differences in lung imaging and SARS-CoV-2 antibody responses in a COVID-19 golden Syrian hamster model

“…Golden Syrian hamsters have already been successfully used in SARS-CoV-2 transmission studies (24, 25, 46), to compare routes of SARS-CoV-2 infection (41, 47), to evaluate convalescent plasma and monoclonal antibody therapy (24, 26, 48-50), and to test therapeutics and vaccines (23, 45). This model provides a unique opportunity to understand the kinetics of SARS-CoV-2 immunopathology not only systemically but also at the site of infection, the respiratory system.…”

Immunological mechanisms of vaccine-induced protection against COVID-19 in humans

“…There are currently >270 candidate COVID-19 vaccines in development, including >90 in clinical trials 5 – 7 . These include nucleic acid vaccines (RNA and DNA) 8 – 11 , human and simian replication-deficient and replication-competent adenoviral-vectored vaccines 12 , 13 , whole-cell inactivated virus 14 , 15 , subunit protein vaccines 16 and virus-like particles 6 . As of April 2021, 28 of these vaccines have entered phase III clinical trials, and 5 (Table 1 ) have reported efficacy in the peer-reviewed literature and/or through detailed publicly available reports submitted to regulatory authorities, resulting in emergency authorizations for their use in a large number of countries.…”