The recently emerged, human coronaviruses, is thought to be originated in bats. A study used a single experimental platform founded on human lung-only mice (LoM) to display efficient in vivo replication of all recently emerged human coronaviruses (SARS-CoV, MERS-CoV, SARS-CoV-2) and two approvingly appropriate endogenous pre-pandemic SARS-like bat coronaviruses. 

This model utilized genuine human lung tissue for virus replication and eliminated the need for adaptation of the virus or the host. The findings were as follows-

• Bats harbor endogenous coronaviruses which have the capability of transmitting directly into humans. 
• In vivo infection of pandemic SARS-CoV-2 in LoM, human lung tissue demonstrated predominant infection of human lung epithelial cells, involving type II pneumocytes found in alveoli and ciliated airway cells. 
• Acute SARS-CoV-2 infection was found to be greatly cytopathic 
• A robust and sustained Type I interferon and inflammatory cytokine/chemokine response was found associated with Acute SARS-CoV-2 infection. 

Thus on evaluating a pre-exposure prophylaxis strategy for coronavirus infection, a prophylactic administration of EIDD-2801 was found to be dramatically associated with SARS-CoV-2 infection prevention in vivo and thus can potentially be used for the prevention and treatment of COVID-19.

Source- Res Sq. 2020;rs.3.rs-80404. doi:10.21203/rs.3.rs-80404/v1