The use of plant systems as bioreactors is steadily gaining more significance in modern biotechnology. Many substances including pharmaceuticals can be produced using transgenic plants. The advantages of plants compared to the conventional bioreactors—microorganisms and animal cell cultures—are product safety and lower production costs. One of the promising approaches for the production of plant bioreactors is to create edible vaccines and adjuvants based on the recombinant antigens and immunoregulatory cytokines, which are proposed for use as biological additives in animal husbandry. The research into the production of plant bioreactors synthesizing the γ-interferons of mammals and birds, which possess the antiviral, antibacterial, antitumor, and immunomodulatory activities, are carried out in the Gene and Cell Engineering Laboratory, St. Petersburg State University.