The disclosure provides anti-DENV antibodies and methods of making and using the same. Nucleic acids encoding anti-DENV antibodies and host cells comprising the nucleic acids are also provided. The anti-DENV antibodies have uses that include treating DENV infection. The disclosure also provided polypeptides containing a variant Fc region and methods of making the same. Nucleic acids encoding polypeptides and host cells comprising the nucleic acids are also provided. The polypeptides have uses that include treating a viral infection. Also claimed is a polypeptide comprising a Fc variant comprising at least one amino acid alteration in a parent Fc region, wherein the variant Fc region has a substantially decreased FcYR-binding activity and does not have a substantially decreased C1 q-binding activity when compared to the parent Fc region.