The coronavirus infects cells by using the spike proteins on its surface to bind to proteins on the surface of human cells known as ACE2 receptors, especially those cells that line the respiratory tract, but other tissues as well, as we saw in chapter 1. After a sequence of steps, the virus enters the cell, where it takes over cellular machinery in order to reproduce itself, releasing more virus into the body, which can both harm the individual and spread to other people.
