The present invention relates to a nucleic acid vaccine. Specifically, the use of a single nucleic acid sequence comprising combinations of influenza genes coding for selected hemagglutinin (HA), neuraminidase (NA), matrix protein 1 (M1), matrix protein 2 (M2) and nucleoprotein (NP) interspaced with selected linkers comprising cleavage sites to produce individual proteins, together forming one polyvalent influenza vaccine for use in medicine for humans and animals.