Evaluation of a new polyvalent Pseudomonas vaccine in respiratory infections

A new polyvalent, cell wall extract, Pseudomonas aeruginosa vaccine (PEV-01), was evaluated by using a guinea pig model of experimental Pseudomonas pneumonia. Guinea pigs routinely developed fourfold rises in serum hemagglutinating Pseudomonas antibodies after four vaccine injections given over 2 weeks. Vaccinated animals survived an intratracheal Pseudomonas challenge (1 X 10(8) colony-forming units) significantly better (13 of 14 survived) than did a control group (5 of 14 survived) (P less than 0.01). Clearance of viable Pseudomonas from lung tissue was significantly better in vaccinees than controls at both 3 h (P less than 0.02) and 6 h (P less than 0.05) after infection. Both gross and histological examinations of lung tissue revealed less pulmonary tissue damage in vaccinated animals following Pseudomonas infection. Thus, PEV-01 Pseudomonas vaccine appears capable of eliciting a specific protective response in the guinea pig respiratory tract.