108 Development of universal vaccines against flu: reality and prospects

Two surface glycoproteins hemagglutinin and neuraminidase are the main antigens for obtaining traditional flu vaccines due to their high immunogenicity and ability to induce generation of neutralizing antibodies. High genetically instability of influenza virus provides antigenic diversity of these glycoproteins between strains. Subunit vaccines based on one of these surface antigens are characterized by narrow specificity. Modern vaccines should provide protection against several or all subtypes of influenza A viruses. In addition sporadic influenza outbreaks of newly emerged influenza A viruses may cause the next pandemic. Today there are no flu vaccines of a wide range of action, so-called “universal” vaccines. Several flu vaccines with a broad cross-protectivity are tested in different phases of clinical trials. In this report the analysis of the modern researches directed on creation of flu “universal” vaccines including data obtained by researchers of Gamaleya institute of epidemiology and microbiology is carried out. Genetic immunization technology is used for development of “universal” vaccine. Recombinant pseudoadenoviral particles coding of influenza virus conservative antigens were used as a vector for gene delivery. Polypeptide, containing hemagglutinin conservative epitopes, was used in addition to traditional influenza conservative antigens M1, M2 and NP. Animal experiments demonstrated that developed vaccines were very efficient against different influenza subtypes (80%–100% survivability).