https://twitter.com/_/status/1362235210302189577

"Pre-existing Tcell immunity to SARSCov2 has been reviewed in several publications.. High % of unexposed healthy subjects with pre-existing immunity suggests that a part of popn likely to have SARSCoV2 reactive Tcells—b/c of prior exposure to common cold-causing coronaviruses"

I wonder what else creates these mysterious t-cells.