Intranasal delivery of an adenovirus-vector vaccine co-expressing a modified spike protein and a genetic adjuvant confers lasting mucosal immunity against SARS-CoV-2.

"Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper."

"The authors would like to acknowledge Dr. Jun Chang of Ewha Womans University (Seoul, Korea) for providing the pShuttle-CMV and pAdEasy-1 vectors. The authors also acknowledge Dr. Masato Tanaka of the Tokyo University of Pharmacy and Life Sciences (Tokyo, Japan) for kindly providing the CD169-DTR mice. The authors thank the members of the Host Defenses Laboratory for helpful discussions and Ji Ye Kim at the BioMedical Research Center in KAIST for technical assistance. This work was supported by the Mobile Clinic Module Project funded by KAIST and the 2020 Joint Research Project of Institutes of Science and Technology. This work was also supported by grants from the 10.13039/501100003725National Research Foundation of Korea (NRF-2021M3A9H3015688) funded by the Ministry of Science and ICT of Korea. Kyun-Do Kim was supported by the convergence platform for infectious disease diagnosis and prevention (NO. KK2333-20) and K-GRC GO! KRICT project (NO. BSF23-113) funded by 10.13039/501100003704Korea Research Institute of Chemical Technology. Hi Eun Jung was supported by the Basic Science Research Program through the National Research Foundation of Korea funded by the Ministry of Education (NRF-2022R1I1A1A01071399)."