Development of antiviral mucosal vaccines involving pH-dependent polymers and polymer complexes is a topical problem now. These polymers are capable of protecting the virus from acid gastric medium and releasing it in weakly alkaline intestinal medium. In addition, the majority of these polymers are capable of intensifying the immune response to the antigen introduced. SRC BV VECTOR with AOZT DELSI elaborated the method of microencapsulation of viral particles into a matrix of pH-dependant polymers under specific condition of their conformational transitions. Spherical or irregular-shaped particles with size of 1–30 µm were produced. Examination of the immunogenic properties of the vaccine specimens has demonstrated the increase in the antibody titers of the animals immunized orally with the preparations containing polyacrylic acid copolymers with ethyl groups, sodium alginate-chitosan complexes and sodium alginate-spermidine complexes.