[Changes in the antigenic properties of influenza virus after sugar cleavage]

Concentrated and purified influenza A/PR/8/34 viruses was treated with a mixture of exoglycosidases for cleavage of carbohydrate part of surface glycoproteins. The hemagglutinating activity of the cleaved virus, its sorption properties, immunogenicity, and capacity to bind homologous antibody were studied. The virions devoid of sugars were shown to lose 50% of their hemagglutinating activity and to be less capable of forming virus-antibody complexes. At the same time the virus with cleaved glycoproteins retained its capacity to adsorb on nonorganic sorbent and stimulate antibody production in animals.