Nucleoside-Modified mRNA Vaccines Protect IFNAR <sup>–/–</sup> Mice against Crimean-Congo Hemorrhagic Fever Virus Infection
Sofia Appelberg, Lijo John, Norbert Pardi, Ákos Végvári, Sándor Bereczky, Gustaf Ahlén, Vanessa Monteil, Samir Abdurahman, Flora Mikaeloff, Mitchell Beattie, Ying Tam, Matti Sällberg, Ujjwal Neogi, Drew Weissman, Ali Mirazimi
Abstract
Crimean-Congo hemorrhagic fever virus (CCHFV) is a zoonotic pathogen causing Crimean-Congo hemorrhagic fever (CCHF), a severe fever disease. CCHFV has a wide distribution and is endemic in several areas around the world. Cases of CCHF are also being reported in new areas, indicating an expansion of the disease, which is of high concern. Dispersion of the disease, high fatality rate, and no approved vaccine makes CCHF a threat to global health. The development of a vaccine is thus of great importance. Here we show 100% protection against lethal CCHFV infection in mice immunized with mRNA-LNP encoding for different CCHFV proteins. The vaccination showed both robust humoral and cellular immunity. mRNA-LNP vaccines combine the ability to induce an effective immune response, the safety of a transient carrier, and the flexibility of genetic vaccines. This and our results from the current study support the development of a mRNA-LNP based vaccine against CCHFV.