[Protection against influenza by genetically engineered vaccines].

Viral vector recombinant DNA vaccines, so called genetically engineered vaccines, are introduced directly into cells to induce an antigen specific immune response. This is a new approach to vaccination that represents a new concept in immunotherapy, which attempts to induce a long-term effective, anti-specific, viral antigen immune response. These vaccines may also prove more potent than currently used vaccines when it comes to inducing cellular immune responses in addition to humoral immune response. In the case of influenza, an immune response with humoral characteristics was induced using an influenza hemagglutinin(HA) DNA vaccine. On the other hand, injection of influenza virus nucleoprotein(NP) induced a Th-1 type cellular immune response including CTL. Genetically engineered vaccines have the potential to effectively overcome the problem of unresponsiveness to currently used vaccines.