The invention relates to a replication-deficient adenoviral vector comprising two or more nucleic acid sequences encoding Dengue virus antigens and a chimeric hexon protein. The chimeric hexon protein comprises a first portion and a second portion. The first portion comprises at least 10 contiguous amino acid residues from a first adenovirus serotype (e.g., serotype 5 adenovirus hexon protein), optionally with one amino acid substitution. The second portion comprises (a) at least one hypervariable region (HVR) of a hexon protein of an adenovirus of a second adenovirus serotype, or (b) at least one synthetic hypervariable region (HVR) that is not present in the hexon protein of the wild-type adenovirus of the first adenovirus serotype.