Disclosed herein are compositions and methods useful for immunizing a subject against disease caused by influenza A. Disclosed methods comprise administering to the subject an immunoprotective dose of an immunogenic composition. In certain aspects, the immunogenic composition is a vaccine comprised of a recombinant chimeric hemagglutinin polypeptide. In certain aspects, the subject is a mammal. In further aspects, the mammal is a pig. In still further aspects, the mammal is a human.