CD4 and nasopharyngeal carcinoma: A second phase I clinical trial of the MVA-EL vaccine conducted in UK showed an increase in CD4+ and CD8+ T-cell responses to one or both of the antigens in 8 of the 14 NPC patients tested, as well as increased differentiation and functional diversification in the EBNA1- and LMP2-specific CD4+ and CD8+ cells (190).