the COVID-19 pandemic has given us a keen sense of how variable the human response to infection can be, vividly dramatizing the ways that a virus or bacterium (or multiple viruses and bacteria) can collide with an individual’s biology to unleash a host of perplexing aftereffects in the body, often incited by the individual’s immune system. The scope of the problem of COVID-19 long haulers has begun to bring more attention to these chronic syndromes.
