Isolated mutant dengue virus E protein variants are disclosed. The variant comprises an amino acid sequence that is at least 80% identical to SEQ ID NO: 1 and has one or more amino acid residue substitutions at position corresponding to Asn8 (N8), Arg9 (R9), Val12 (V12) and/or Glu13 (E13). The variant may comprise an amino acid sequence that is at least 90% identical to the SEQ ID NO: 1 and lack an infection-enhancing antibody-binding motif comprising the amino acid sequence of SEQ ID NO: 28 at domain I. An isolated nucleic acid sequence encoding the variant, a plasmid expressing the variant, a plasmid expressing a virus-like particle comprising the variant, a DNA vaccine, and a method of detecting the presence of a dengue virus in a biological sample are also disclosed.分離的突變登革熱病毒E蛋白變體被揭露。該變體包含一胺基酸序列，該胺基酸序列與SEQ ID NO：1具有至少80%的相似度，且在天冬醯胺酸8(N8)、精胺酸9(R9)、纈胺酸12(V12)及/或麩胺酸13(E13)的對應位置上具有一或多個胺基酸殘基取代基。該變體可包含一胺基酸序列，該胺基酸序列與SEQ ID NO：1具有至少90%的相似度且缺乏一包含在結構域I的SEQ ID NO：28胺基酸序列的感染性增強抗體結合模體。一種編碼該變體的分離的核酸序列、一種表現該變體的質體、一種表現一包含該變體的病毒樣顆粒的質體、一種DNA疫苗，以及一種檢測在一生物樣品中登革熱病毒存在的方法也被揭露。
