Recombinant lactic acid bacteria and the use thereof in oral universal influenza vaccine

An oral formulation for targeting a variety of influenza viruses causing influenza and treating said influenza in a subject in need thereof comprising a recombinant lactic acid bacterial cell transformed with an expression vector containing an encoding sequence for encoding a fusion protein comprising a fluorescent protein, a stem domain of influenza hemagglutinin, a ferritin protein and two linkers, and a pharmaceutically acceptable carrier, wherein the encoding sequence encoding the fluorescent protein and encoding the stem domain of influenza hemagglutinin have been codon optimized for expression in lactic acid bacteria and wherein in the fusion protein said two linkers link the stem domain of influenza hemagglutinin, the fluorescent protein, and the ferritin protein.