Mild weight loss and clinical scores in wild‐type mice. High viral replication in the lung during the early stages of infection rapidly decreases with disease progression. Increased severity in immunocompromised mice that is dependent on the knockout line used (e.g., IFNAR). This model is advantageous for understanding genetic determinants of SARS‐CoV‐2 infection dependent on the mouse line used; however, is not suitable for drug or vaccine studies. This evidence concerns the gene IFNAR1 and infection.