The Plague Year: America in the Time of Covid

by Lawrence Wright

“There are three things this virus is doing that blow me away,” said Brooks, marveling at the resourcefulness and agility of his adversary. “The first is that it directly infects the endothelial cells that line our blood vessels. I’m not aware of any other respiratory viruses that do this. This causes a lot of havoc.” Endothelial cells provide a protective coating inside the blood vessels, sealing off the cell like a Ziploc bag. They modulate blood pressure and serve as traffic cops, using sticky proteins to nab passing immune cells and direct them where they are needed when a threatening virus is present. With coronaviruses, the vulnerable spot for infection in humans is the ACE2 receptor. If the virus is the key, the receptor is the lock it’s looking for. ACE2 receptors are enzymes found in the lungs and kidneys as well as in the gut and the brain, accounting for the many manifestations of the disease in humans. They are also abundantly present in the endothelial cells. The virus binds to these receptors, hijacking the cell’s machinery to make copies of itself, thereby killing the cell and scouring the thin cell wall, which generates turbulent blood flow. Powerful chemical contents get dumped into the bloodstream, stirring up inflammation elsewhere in the body. Brooks had never seen that condition before. The second surprise was hypercoagulability—a pronounced tendency to develop blood clots. Brooks was reminded of Michael Crichton’s 1969 best-selling thriller, The Andro...