Abstract: | After immunization of guinea pigs with Shigella sonnei ribosomal vaccine O-antibodies appeared not only in the blood serum of the animals, but also in their lacrimal fluid. Since no correlation between the levels of serum and secretory antibodies was detected and since the time course of changes in these antibody levels was quite different (serum antibodies reached their peak on day 7 while secretory antibodies, on day 14 after vaccination), antibodies in lacrimal fluid were supposed to reflect local immune response induced by parenteral administration of ribosomal vaccine, irrespective of systemic immune response. The peak of secretory O-antibodies coincided in time with the period of the highest protection of guinea pigs from Shigella keratoconjunctivitis. The animals with a high level of secretory antibodies were better protected from Shigella infection than those with a low level of secretory antibodies. These data suggest that locally produced O-antibodies play an important role in protective immunity induced by parenteral administration of the ribosomal vaccine. |