Since almost all the current COVID‐19 vaccines are administered intramuscularly, their effect in inducing mucosal immunity is lower than in the recovered patients, while the antibody response to the vaccinated recipients' peripheral blood was significant.[7] In addition, compared with recovered patients, vaccine recipients had few S protein‐specific T cells and B cells in BAL.[7a] In this study, we found intranasal vaccination with the mosaic vaccine induced superior neutralizing IgA and IgG secretion in the lung than that by subcutaneous immunization in mice. This evidence concerns the gene CD79A and COVID-19.