Figure 6.

The life cycles of the SARS-CoV-1/2, SARS-CoV-1 (SARS1) produces more infectious particles, especially in vital organs arising from the differences in N PIDs but sheds fewer infectious particles orally and nasally because its outer shell (M) is not as hard and protective as that of SARS-CoV-2. SARS1 and SARS-CoV-2 have different life cycles as a result of the differences in the S proteins. This is denoted by the differences in the lengths of their life cycles and the number of particles at viral entry. Note: Numbers of infectious particles shown are comparative and qualitative illustrations and are not to meant to be exact quantifications.