Influenza virus antigens conjugated with a synthetic polyelectrolyte: a novel model of vaccines.

Haemagglutinin (HA), a mixture of haemagglutinin and neuraminidase (HA + NA), and matrix (M) protein were isolated from the influenza A virus and covalently coupled to a synthetic polyelectrolyte (P). A single injection into mice of the resultant conjugates (virogates) brought about efficient stimulation of the primary immune response specific to the corresponding viral antigens. Mice immunized with virogates HA.P or (HA + NA).P were largely protected against a lethal challenge infection with homologous virus. Immunization of mice with M.P virogate containing M protein originated from a 1934 influenza strain resulted in pronounced protection against a lethal challenge infection with a 1980 strain. Virogates are discussed as a novel model of artificial vaccines.