RESUMEN
The potential emergence of deadly pandemic influenza viruses is unpredictable and most have emerged with no forewarning. The distinct epidemiological and pathological patterns of the Spanish (H1N1), pandemic-2009 (H1N1), and avian influenza (H5N1), known as bird flu, viruses may allow us to develop a 'template' for possible emergence of devastating pandemic strains. Here, we provide a detailed molecular dissection of the structural and nonstructural proteins of this triad of viruses. GenBank data for three representative strains were analyzed to determine the polymorphic amino acids, genetic distances, and isoelectric points, hydrophobicity plot, and protein modeling of various proteins. We propose that the most devastating pandemic strains may have full-length PB1-F2 protein with unique residues, highly cleavable HA, and a basic NS1. Any newly emerging strain should be compared with these three strains, so that resources can be directed appropriately.