Protection by vaccination against Pseudomonas infection after thermal injury.

Active immunization is effective in the prophylaxis of Pseudomonas septicemia in burned mice. Vaccines were prepared from bacterial cells and growth medium of Verder's 10 different O serological types of Pseudomonas aeruginosa strains, as well as from Escherichia coli and Proteus mirabilis. Mice given a tail burn could be significantly protected against a local Pseudomonas challenge by both specific and, to a lesser extent, by nonspecific Pseudomonas vaccines prepared either from bacterial cells or from the medium in which they were grown. The vaccine was effective when administered prior to or after thermal trauma. After a more extensive rump burn, the protective effect of a specific vaccine given after thermal injury was significant only when the challenge was postponed until 4 days postburn; the level of protection was less than in the mice with smaller burns.