CXCR3 and COVID-19: Previous studies have shown that SARS-CoV-2 infection induces robust spike-specific TH1 and TFH cell responses in the acute phase that are maintained in the convalescent phase and persist for several months to a year.41,42,57 Here, in a longitudinal analysis of circulating TFH cells over a 2-year period in COVID-19 convalescents, we found that spike-specific CXCR3+ TFH cell response persisted for up to 24 months or more.