The invention relates to an attenuated variant of the Rift Valley Fever Virus (RVFV) with mutations in the amino acid sequence coded by segments L, M and S of RVFV RNA; a pharmaceutical or veterinary composition comprising same; an attenuated RVFV variant for use in the prevention of Rift Valley Fever; and a vaccine against Rift Valley Fever comprising the attenuated RVFV variant. Attenuated RVFV variants with the mutations Gly924Ser and Ala303Thr in protein L, and the Pro82Leu substitution in protein NSs, are also included.

Nucleic acid molecules and compositions comprising one or more nucleic acid sequences that encode a consensus Crimean-Congo hemorrhagic fever virus (CCHFV) antigens. Immunomodulatory methods and methods of inducing an immune response against CCHFV are disclosed. Method of preventing infection by CCHFV and methods of treating individuals infected with CCHFV are disclosed. CCHFV glycoprotein immunogens are disclosed.

The present disclosure relates to a vaccine composition for preventing or treating infectious diseases caused by severe fever with thrombocytopenia syndrome (SFTS) virus.

Disclosed herein is a robust system for the reverse genetics generation of a Rift Valley fever (RVF) virus replicon particle (VRP.sub.RVF) vaccine candidate. VRP.sub.RVF can actively synthesize viral RNA and proteins, but lack structural glycoprotein genes, preventing spread within immunized individuals and reducing the risk of vaccine-induced pathogenicity. Is it disclosed herein that VRP.sub.RVF immunization is both safe and efficacious, resulting in a robust immune response that is protective against RVF virus challenge within 24 hours of immunization. Provided herein are VRP.sub.RVF, methods of producing VRP.sub.RVF, and method of using VRP.sub.RVF for immunization against RVF virus infection.

Nucleic acid molecules and compositions comprising one or more nucleic acid sequences that encode a consensus Crimean-Congo hemorrhagic fever virus (CCHFV) antigens. Immunomodulatory methods and methods of inducing an immune response against CCHFV are disclosed. CCHFV glycoprotein immunogens are disclosed.

The invention relates to an attenuated variant of the Rift Valley Fever Virus (RVFV) with mutations in the amino acid sequence coded by segments L, M and S of RVFV RNA; a pharmaceutical or veterinary composition comprising same; an attenuated RVFV variant for use in the prevention of Rift Valley Fever, and a vaccine against Rift Valley Fever comprising the attenuated RVFV variant. Attenuated RVFV variants with the mutations Gly924Ser and Ala303Thr in protein L, and the Pro82Leu substitution in protein NSs, are also included.