CD4 and tuberculosis: Rosas Mejiaet al. showed that Mtb-infected mice were resistant to the pathological consequences of secondary SARS-CoV-2 infection, but that SARS-CoV-2 infection did not affect Mtb burdens in the lungs or distant organs.10 Bakeret al. also found no difference in TB burden between mice with prior SARS-CoV-2 and those without, and that Mtb/SARS-CoV-2 coinfection did not affect the proportions of pulmonary Mtb-specific CD4+ and CD8+ T cells, but did significantly reduce the proportion of SARS-CoV-2-specific CD4+ and CD8+ T cells.12