CD27 and infection: While the B15/S919+CD8+ T cells had predominantly CD45RA−CD27+ central memory-like phenotype in both prepandemic and post-SARS-CoV-2 infection samples, infection still resulted in a decrease in CD45RA+CD27+CD95- naïve-like B15/S919+CD8+ T cells by 1 mo (Fig. 1E).