Some people carry immune cells called T cells that can capitalize on the virus’s resemblance to other members of its family tree.
- Aug. 6, 2020
Eight months ago, the new coronavirus was unknown. But to some of our immune cells, the virus was already something of a familiar foe.
A flurry of recent studies has revealed that a large proportion of the population — 20 to 50 percent of people in some places — might harbor immunity assassins called T cells that recognize the new coronavirus despite having never encountered it before.
These T cells, which lurked in the bloodstreams of people long before the pandemic began, are most likely stragglers from past scuffles with other, related coronaviruses, including four that frequently cause common colds. It’s a case of family resemblance: In the eyes of the immune system, germs with common roots can look alike, such that when a cousin comes to call, the body may already have an inkling of its intentions.