CD4 and COVID-19: To better understand the potential impact of COVID-19 on M. tuberculosis coinfection, we compared the frequency and phenotype of M. tuberculosis–specific CD4+ T cells in COVID-19 patients, hospitalized non–COVID-19 controls, and outpatient participants with latent TB (LTBI) or aTB recruited to unrelated studies prior to the emergence of the COVID-19 pandemic (Supplemental Table 3).