摘要
The rapid mutation and spread of SARS-CoV-2 variants urge the development of effective mucosal vaccines to provide broadspectrum protection against the initial infection and thereby curb the transmission potential.Here,we designed a chimeric tripleRBD immunogen,3Ro-NC,harboring one Delta RBD and two Omicron RBDs within a novel protein scaffold.3Ro-NC elicits potent and broad RBD-specific neutralizing immunity against SARS-CoV-2 variants of concern.Notably,intranasal immunization with 3RoNC plus the mucosal adjuvant KFD(3Ro-NC+KFDi.n)elicits coordinated mucosal IgA and higher neutralizing antibody specificity(closer antigenic distance)against the Omicron variant.In Omicron-challenged human ACE2 transgenic mice,3Ro-NC+KFDi.n immunization significantly reduces the tissue pathology in the lung and lowers the viral RNA copy numbers in both the lung(85.7-fold)and the nasal turbinate(13.6-fold).Nasal virologic control is highly correlated with RBD-specific secretory IgA antibodies.Our data show that 3Ro-NC plus KFD is a promising mucosal vaccine candidate for protection against SARS-CoV-2 Omicron infection,pathology and transmission potential.
基金
This work was supported in whole or in part by the National Key R&D Program of China(grant number:2021YFC2302602 to JY)
the strategic priority research program(grant number XDB29010101)
key project(2020YJFK-Z-0149)of the Chinese Academy of Sciences(to Z-LS)
This study was also supported by the National Natural Science Foundation of China(31970878 to JY,92169104 and 31970881 to Y-QC),Shenzhen Science and Technology Program (Grant number: RCJC20210706092009004 and JCYJ20190807154603596 to Y-QC).
