A menu of mutations was developed that is useful in fine-tuning the attenuation and growth characteristics of dengue virus vaccines.

The present invention relates to a genomic sequences encoding for an attenuated mutant Zika virus. The inventors have introduced some specific substitutions at very specific positions in the epidemic genomic sequence for restoring some fixation sites for miR-4279 that were originally present in the endemic genomic sequence. Moreover the inventors have additionally introduced mutation leading to the abrogation of the N-glycosylation site on the E protein which will prevent the generation of auto-antibodies responsible for Guillain-Barre syndrome. The inventors have produced additional mutations of the virus that result to a dramatic reduction of the cytopathic effects without affecting the capacity to produce high titers of virus. In particular the present invention relates to a genomic sequence characterized by the sequence represented by SEQ ID NO:1 wherein at least one site of fixation for miR-4279 is restored.

Embodiments herein report compositions, uses and manufacturing of dengue virus constructs and live attenuated dengue viruses. Some embodiments concern a composition that includes, but is not limited to, a tetravalent dengue virus composition. In certain embodiments, compositions can include constructs of one or more serotypes of dengue virus, such as dengue-1 (DEN-1) virus, dengue-2 (DEN-2) virus, dengue-3 (DEN-3) or dengue-4 (DEN-4) virus constructs. In other embodiments, constructs disclosed herein can be combined in a composition to generate a vaccine against more one or more dengue virus constructs that may or may not be subsequently passaged in mammalian cells.

The present invention relates to attenuated, immunogenic West Nile virus chimeras built on a dengue virus backbone for the production of immunogenic, live, attenuated West Nile virus vaccines.

Embodiments herein report compositions, uses and manufacturing of dengue virus constructs and live attenuated dengue viruses. Some embodiments concern a composition that includes, but is not limited to, a tetravalent dengue virus composition. In certain embodiments, compositions can include constructs of one or more serotypes of dengue virus, such as dengue-1 (DEN-1) virus, dengue-2 (DEN-2) virus, dengue-3 (DEN-3) or dengue-4 (DEN-4) virus constructs. In other embodiments, constructs disclosed herein can be combined in a composition to generate a vaccine against more one or more dengue virus constructs that may or may not be subsequently passaged in mammalian cells.

The invention is related to a dengue virus or chimeric dengue virus that contains a mutation in the 3 untranslated region (3-UTR) comprising a 30 mutation that removes the TL-2 homologous structure in each of the dengue virus serotypes 1, 2, 3, and 4, and nucleotides additional to the 30 mutation deleted from the 3-UTR that removes sequence in the 5 direction as far as the 5 boundary of the TL-3 homologous structure in each of the dengue serotypes 1, 2, 3, and 4, or a replacement of the 3-UTR of a dengue virus of a first serotype with the 3-UTR of a dengue virus of a second serotype, optionally containing the 30 mutation and nucleotides additional to the 30 mutation deleted from the 3-UTR; and immunogenic compositions, methods of inducing an immune response, and methods of producing a dengue virus or chimeric dengue virus.

Provided are an attenuated virus of a flavivirus virus and the use thereof. The attenuated virus comprises a polyadenylic acid (poly(A)) sequence, wherein the polyadenylic acid (poly(A)) is used for replacing a part of the nucleotide sequence of a 3 untranslated region (3UTR) of the flavivirus virus, so that the 3 untranslated region (3UTR) of the attenuated virus obtained after the part of the nucleotide sequence of the flavivirus virus is replaced at least retains a 3-end stem loop region (3SL). The attenuated virus can be used for preparing safe and effective attenuated vaccine strains.

Compositions that specifically cleave target sequences in Flavivirus, for example Zika virus include a Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR) associated endonuclease, a guide RNA sequence complementary to a target sequence in a Zika virus and an anti-viral agent. These compositions are administered to a subject for treating an infection or at risk for contracting a Zika virus infection.

Nucleic acid molecules comprising a coding sequence with at least one codon substituted to a synonymous codon, a modified form of a virus comprising the nucleic acid molecules of the invention, and methods for producing these nucleic acid molecules, and viruses, are provided.

Disclosed herein are chimeric flaviviruses including non-coding regions, non-structural proteins, and at least a portion of a C protein from West Nile virus (WNV), and a prM protein and an E protein from Dengue virus (DENV). The DENV may be DEN1 serotype, DEN2 serotype, DEN3 serotype, or DEN4 serotype. Also disclosed herein are compositions and methods for eliciting an immune response in a subject, such as an immune response to one or more DENV serotypes. In particular embodiments, the compositions include one or more inactivated viruses including a WN/DENV chimeric nucleic acid (such as a tetravalent inactivated vaccine including a WN/DEN1 chimera, a WN/DEN2 chimera, a WN/DEN3 chimera, and a WN/DEN4 chimera). The compositions may be administered to a subject to elicit an immune response.