Clinical and immunological characteristics of the emulsion form of inactivated influenza vaccine delivered by oral immunization.

Prophylaxis of human respiratory diseases caused by influenza viruses is actually a problem of infectious pathology because of their wide prevalence. In our investigations, safety, reactogenicity and immunological activity of the orally administered emulsion-inactivated influenza vaccine prepared from influenza virus strains of types A(H1N1), A(H3N2) and B have been studied. Clinical studies of the emulsion-inactivated influenza vaccine on volunteers has shown its safety and nonreactogenicity. The orally administered vaccine did not cause weak, middle or strong general or local reactions including clinical, biochemical, haemotological and immunological reactions. The emulsion-inactivated vaccine has high immunological activity and induces reliable increases in the level of secretory immunoglobulin A to influenza viruses A and B in protective titers in nasal secretions and saliva of volunteers after one oral administration. The obtained results indicate the expediency of further investigation and improvement of inactivated influenza vaccine for oral administration.