CD4 and influenza: Flagellin represents an appropriate platform for the development of recombinantvaccines against various pathogens of viral and bacterial origin[2, 28].The adjuvant effect of flagellin is mediated via the TLR5 signaling pathway inCD11c+ antigen-presenting cells, which explains the increase in the immunogenicpotential of antigens fused to flagellin and the ability to enhance the CD4+T-mediated humoral response[28-31].The role of flagellin as a vaccine platform and an adjuvant at the same time has beendemonstrated in multiple infection models, including influenza[2, 6,27,32-34].