Compartmentalized SARS-CoV-2 Replication in the Upper vs Lower Respiratory Tract After Intranasal Inoculation or...

Area of Science:

• Virology
• Infectious Diseases
• Immunology

Background:

• Nonhuman primate models, specifically rhesus macaques, are crucial for studying infectious diseases like SARS-CoV-2.
• Understanding viral tropism and replication patterns is key to developing effective vaccines and antivirals.

Purpose of the Study:

• To compare the cellular tropism and virus replication of SARS-CoV-2 in rhesus macaques following intranasal inoculation versus aerosol exposure.
• To evaluate the impact of different inoculation routes on the extent of respiratory tract infection.

Main Methods:

• Rhesus macaques were inoculated with SARS-CoV-2 using either the intranasal route or via exposure to aerosols.
• Cellular tropism and virus replication were assessed in various parts of the respiratory tract.

Main Results:

• Intranasal inoculation led to SARS-CoV-2 replication primarily in the upper respiratory tract, with minimal lower respiratory tract involvement.
• Aerosol exposure resulted in infection and virus replication throughout the entire respiratory tract.
• Both intranasal and aerosol inoculation routes demonstrated reduced SARS-CoV-2 replication compared to multiroute inoculation.

Conclusions:

• The route of SARS-CoV-2 inoculation significantly influences viral tropism and replication patterns in rhesus macaques.
• Aerosol exposure leads to a more disseminated respiratory infection than intranasal inoculation.
• Intranasal and aerosol routes may offer controlled models for studying SARS-CoV-2 pathogenesis and evaluating countermeasures.