The present invention provides, among other things, antibody agents (e.g., antibodies, and/or antigen-binding fragments thereof) that bind to DV epitopes, as well as compositions containing them and methods of designing, providing, formulating, using, identifying and/or characterizing them. In some embodiments, provided antibody agents show significant binding to a plurality of DV serotypes. In some embodiments, provided antibody agents show significant binding to all four DV serotypes. Such antibody agents are useful, for example, in the prophylaxis, treatment, diagnosis, and/or study of DV.