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 Δ30 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 Δ30 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 Δ30 mutation and nucleotides additional to the Δ30 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.

The present invention discloses a live attenuated strain of Zika virus (ZIKV) having a deletion in the 3′ untranslated region (3′UTR) of the viral genome, which may affect viral RNA synthesis and sensitivity to type I interferon inhibition, but may not affect viral RNA translation. The present invention also discloses the use of these live attenuated ZIKV strains in the preparation of ZIKV vaccines and for providing immunoprotection against ZIKV infection and congenital ZIKV syndrome, particularly in pregnant females.

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

Attenuated viruses and methods of designing them are disclosed. In one embodiment, there is disclosed an attenuated form of a virulent virus comprising an RNA encoding a viral protein or a nucleic acid sequence transcribable to said RNA, wherein the folding energy or structure of the RNA is changed at positions of evolutionarily conserved RNA structures with respect to that of said RNA encoding said viral protein in the virulent virus so as to bring about attenuation of the virus.

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 Δ30 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 Δ30 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 Δ30 mutation and nucleotides additional to the Δ30 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.

Attenuated viruses and methods of designing them are disclosed. In one embodiment, there is disclosed an attenuated form of a virulent virus comprising an RNA encoding a viral protein or a nucleic acid sequence transcribable to said RNA, wherein the folding energy or structure of the RNA is changed at positions of evolutionarily conserved RNA structures with respect to that of said RNA encoding said viral protein in the virulent virus so as to bring about attenuation of the virus.

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,

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 Δ30 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 Δ30 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 Δ30 mutation and nucleotides additional to the Δ30 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.

This invention relates to a vaccine comprising live attenuated Zika virus comprising a partly codon deoptimized viral genome, a Zika virus comprising a partly codon deoptimized viral genome, as well as their use in methods of treatment and prevention of viral infection. is deoptimized along the nonstructural ZIKV coding region. In some embodiments, the non-structural region of the viral genome is codon deoptimized, and preferably one or more of the genes NS1, NS2A, NS2B, NS3, NS4A, NS4B and NS5 are codon deoptimized.

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.