While the hemagglutinin (HA) surface protein is conventionally the primary target of strain-specific influenza DNA vaccines, conserved viral epitopes have the potential to induce immunity against diverse influenza strains. Two highly conserved influenza viral proteins, NP and M2, have been widely targeted as possible broadly protective vaccine candidates [1] [2] [3] [4] [5] [6] [7] [8] [9] . The main function of the nucleoprotein is encapsidation of the viral genome to form a ribonucleoprotein particle for transcription and packaging. NP also interacts with other viral proteins (PB1, PB2, and M1) and cellular proteins (Importin a, F-actin, CRM1/exportin1) for viral transcription control and nuclear transportation control [10] . M2 is responsible for protein translocation, and is expressed at a high density in the plasma membrane of infected cells in tetramer forms. This ion channel protein is also a target for the antiviral drugs amantidine and rimantadine, which control viral replication and have been used for influenza prophylaxis and treatment [11] .