Influenza vaccines with the ability to induce immune responses cross-reacting with drifted virus variants would be of great advantage for vaccine development against seasonal and emerging new strains. We demonstrate that gene gun administrated DNA vaccine encoding HA and NA and/or NP and M proteins of the H1N1 pandemic virus from 1918 induce protection in ferrets against infection with a H1N1 (A/New Caledonia/20/99(H1N1)) virus which was included in the conventional vaccine for the 2006-2007 season. The viruses are separated by a time interval of 89 years and differ by 21.2% in the HA1 protein. These results suggest not only a unique ability of the DNA vaccines, but perhaps also natural infection, to induce cross-protective responses against even extremely drifted virus variants.