AL18, an inhibitor of human cytomegalovirus DNA polymerase, was serendipitously found to also block the interaction between the PB1 and PA polymerase subunits of influenza A virus. Furthermore, AL18 effectively inhibited influenza A virus polymerase activity and the overall replication of influenza A and B viruses. A molecular model to explain the binding of AL18 to both cytomegalovirus and influenza targets is proposed. Thus, AL18 represents an interesting lead for the development of new antivirals
