Sensitizing activity to egg protein of an A1PO4-adjuvant full-virus influenza vaccine

The sensitizing activity to egg protein of an A1PO4-adjuvant purified and concentrated influenza-A vaccine was examined in animal experiments and in man. Intravenous injection of ovalbumin caused anaphylactic symptoms and/or fatal anaphylactic shock in prevaccinated guinea-pigs. Ovalbumin-specific antibodies detectable by the passive haemagglutination reaction (PHA) appeared in the blood serum of the vaccinated animals. Model experiments with purified ovalbumin suggested that 1 human dose of the vaccine contained egg protein in the range from 0.1 to 1 ng, and that the antigenic effect of the vaccine grew to more than 10(3)-fold by its adsorption to A1PO4 gel. Adults who in previous years had been immunized with similarly prepared influenza vaccine several times responded with mild reactions; symptoms suggestive of hyperergy did not occur, irrespective of the vaccination history. In the prevaccination serum sample of some vaccines, ovalbumin-specific PHA antibodies were found up to titres independent of the number of the previous immunizations. The concentration of the ovalbumin-specific antibodies of the IgE class was by several orders of magnitude lower in the postvaccination samples than in the serum of some patients hypersensitive to egg protein.