Compounds, compositions, and methods of treatment and prevention of Hepacivirus, Pestivirus, Flavivirus or Alphavirus infection are disclosed. The compounds are pyrrolo[2,3-b]pyridines and pyrrolo[2,3-b]pyrimidine JAK inhibitors. Combinations of these JAK inhibitors and additional antiretroviral compounds, such as NRTI, NNRTI, integrase inhibitors, entry inhibitors, protease inhibitors, and the like, are also disclosed. In one embodiment, the combinations include a combination of adenine, cytosine, thymidine, and guanine nucleoside antiviral agents, optionally in further combination with at least one additional antiviral agent that works via a different mechanism than a nucleoside analog. This combination has the potential to eliminate the presence of Hepacivirus, Pestivirus, Flavivirus or Alphavirus in an infected patient.