The present invention provides a polynucleotide, polypeptide, recombinant modified vaccinia virus Ankara (rMVA) and related vaccine compositions and methods useful in the prevention and treatment of an influenza viral infection. Provided is an isolated polynucleotide encoding multiple copies of M2 infuenza ectodomain peptides or rMVA comprising the polynucleotide. Also provided are methods for inducing an immune response to a subject against an influenza virus or for treating a disease or symptom caused by or resulting from infection with an influenza virus.