Wei Ye, Yamei Dang, Yuan Wang, Qiqi Yang, Hui Zhang, Chuantao Ye, Jing Wei, Jiawei Pei, Xuemin Pei, Du Jiang, Xiaojing Yang, Xiaolei Jin, Hongwei Ma, He Liu, Liang Zhang, Linfeng Cheng, Yangchao Dong, Yingfeng Lei, Zhikai Xu, Fanglin Zhang
Old World orthohantaviruses, including Hantaan virus (HTNV), cause hemorrhagic fever with renal syndrome (HFRS) in Eurasia. Available inactivated vaccines often induce low neutralizing antibodies and short-term protection. We evaluated nucleic acid vaccines expressing a prefusion-stabilized HTNV glycoprotein in female BALB/c mice. Both DNA and mRNA-LNP versions elicited robust neutralizing antibodies by strongly activating germinal centers, which protected mice against high-dose HTNV challenge. We further tested heterologous prime-boost regimens, where mice primed with inactivated vaccine received different boosters. All boosters increased neutralizing titers, but only the prefusion-stabilized glycoprotein mRNA-LNP vaccine raised titers to the level achieved by its own full primary vaccination course. This demonstrates the immunogen's superiority in developing next-generation vaccines and its unique ability to potently recall memory B cells induced by suboptimal inactivated vaccines. Thus, prefusion-stabilized glycoprotein-based nucleic acid vaccines are promising candidates for advanced orthohantavirus vaccine development.