Qdenga-induced dengue caused by minor DENV-2 subvariant(s) in the vaccine, with two amino acid substitutions in the E protein

Highlight: We describe a Qdenga-induced DENV-2-infection in a Swedish traveller. Comparative sequencing suggests that the vaccine contained a small fraction of identical virus as detected in the patient, suggesting a selection of a DENV-2-substrain with unusual amino acid substitutions. Further research on selection of, and possible effects of, Qdenga-substrain-infections is warranted.