The present invention relates to mutant peptides of the E protein of the West Nile virus and other flaviviruses useful for discriminating flaviviral infections, as well as kits, methods and uses related thereto.

Described herein are next generation vaccine compositions, including mRNA vaccines having flavivirus untranslated regions and vaccines comprising a (major histocompatibility complex) MHC binding peptide.

Embodiments herein concern compositions, methods, and uses for inducing an immune response to all four dengue virus serotypes in a child or young adult from about 1 year to about 20 years of age. Some embodiments concern compositions that can include, but are not limited to, dengue virus chimeras that, either alone or in combination with other constructs, can be used in a vaccine composition against all four dengue virus serotypes. In certain embodiments, compositions can include constructs of more than one serotypes of dengue virus, such as dengue-1 (DEN-1) virus, dengue-2 (DEN-2) virus, dengue-3 (DEN-3) virus and/or dengue-4 (DEN-4) virus, at various concentrations or ratios in order to improve protection from infection in children and young adults. In certain embodiments, viruses of the formulations are limited to dengue virus serotypes. Other embodiments concern methods of administering immunogenic compositions against dengue virus that can include chimeric dengue constructs and live, attenuated dengue viruses using single, dual or other regimens.