CD4 and COVID-19: The targets of the T cell responses in COVID-19 patients is also interesting; unlike other coronaviruses, where the spike protein is thought to be the major dominant T cell epitope [86], in the case of SARS-CoV-2, the spike, nucleocapsid as well as matrix proteins are co-dominant CD4 T cell epitopes, and CD8 T cell targets include both the spike and M protein [76].