In May 2020, a man was hospitalized and, soon after, diagnosed with Covid-19. Within weeks he recovered and went home, only to be readmitted the following month when his Covid-19 symptoms came back with a vengeance. This time he was administered, at distinct yet overlapping intervals, a plurality of treatments, including the steroid dexamethasone; two rounds of remdesivir, an experimental drug therapy; and convalescent plasma from not one, not two, but three different patients. The man, his body unable to mount the resistance it needed to clear out the virus, succumbed to the disease in late August.
Over the course of the man’s hospitalization, researchers extracted, sequenced, and analyzed more than 20 different viral samples, a process they describe in a research paper currently undergoing peer review. They witnessed the virus evolving in real time, and over the course of 100-plus days noted the emergence of several mutations. One way to interpret this is that each time the man was given, via the blood plasma of previously recovered Covid-19 patients, a new mix of anti-SARS-CoV-2 antibodies, the virus found new ways to resist neutralization. In other words, we might be looking at a classic case of immune evasion, a term that refers to the sum total of strategies a virus uses to evade or otherwise overcome the immune system.
Originally published on Forbes (January 11, 2021)