To test our hypothesis that heterologous immunity exists between SARS-CoV-2– and IAV-specific memory CD8+ T cell responses, we stimulated whole blood samples from convalescent patients with COVID-19 with aAPCs loaded with a pool of 6 SARS-CoV-2 T epitopes that had previously been confirmed using unbiased ex vivo screens (26). Here, CD8A is linked to COVID-19.