Figure 2.

Venn diagram of convalescent patients [n (%)] with detectable SARS-CoV-2 reactive T cells as determined by enzyme-linked immunospot (ELISpot) analysis after stimulation with the various Spike (S)-peptide pools. The S protein is responsible for entry into the host cell and consists of two subunits: The S1 subunit contains the receptor-binding domain, which binds to the host cell receptor; the S2 subunit subsequently mediates the fusion of the viral envelope and cell membrane. No SARS-CoV-2 specific T cell response to any S peptide/protein antigen used was detectable in 30 patients.