Understanding the pathogenicity of COVID-19 can give us crucial insights into not only how the disease is spread but also the drug and vaccine development process. This strain of virus comes from a family that has other strains like the SARS-CoV and MERS-CoV which have previously infected humans and were a great public health threat. They were controlled and managed before they spread globally. The difference in the epidemiology probably arises from the fact that SARS-CoV 2 has a greater respiratory load and the people infected with this virus can transmit it while they are asymptomatic. This makes the control and management of the virus exceptionally hard as people continue to be active members of the society, not realizing that they are passing on the virus until it is too late. According to the WHO, the incubation period for this virus ranges from one to fourteen days which can partly explain why it is spreading so quickly.
Delving into the specifics of the biology of COVID-19, it is a betacoronavirus that encodes spike, a surface glycoprotein which can bind to the host-cell receptor and mediate the entry of the virus. The spike protein has a receptor binding domain that interacts with the receptors on the host cell. After the virus binds to the receptor, a host protease cleaves the spike protein which releases a peptide that facilitates virus entry. Studies have confirmed that SARS-CoV-2 spike protein uses human ACE2 receptors. This is a very important finding as it explains why this virus particularly targets the lungs, because that is where the ACE2 receptors are found.
- By: Sanya Bansal