Enhancing the effectiveness of anti-respiratory virus vaccines by bolstering mucosal immunity and cellular defenses

A schematic diagram of intratracheal (IT) boosting, which leads to enhanced mucosal immunity and protective efficacy. IT boosting leads to significant expansion of mucosal neutralizing antibodies, along with robust CD8(+) and CD4(+) T-cell responses. Notably, IT boosting results in substantial and sustained activation of cytokine, natural killer, T, and B-cell pathways in the lung, contributing to enhanced mucosal immunity and overall protective efficacy.