[Control of subunit influenza vaccines]

Influenza subunit vaccines contain essentially only the envelope spike proteins, haemagglutinin (HA) and neuraminidase (NA). It is important to check the purity of each monovalent batch of these vaccines, in comparison with whole virus preparation. The authors have standardized a biochemical analysis for the laboratory control of this kind of vaccines, using PAGE test. All the vaccine manufactures are required to demonstrate, by this method, that the subunit vaccine contains HA and NA, with no more than trace amounts of internal proteins.