To optimize the immunological efficacy of CFC-101, an outer-membrane protein vaccine purified from relatively less pathogenic 4 different Pseudomonas aeruginosa strains, we investigated to establish its dose, administration route, interval and frequency of vaccination in mice. As expected, the 4 CFC-101 producing strains were less pathogenic than the challenging organism, P. aeruginosa GN11189. CFC-101 completely protected the death caused by P. aeruginosa at above 0.05 mg/kg vaccinized by 3 times with 7-day intervals. At the optimally effective dose of 0.2 mg/kg of CFC-101, at least 3 immunizations were necessary for complete protection against P. aeruginosa-induced death. If immunized 3 times, the immunization interval could be shortened up to 2 days to acquire the best protection against P. aeruginosa. CFC-101 was effective either by intraperitoneal, subcutaneous or intramuscular but not by oral administration. The present results show that the newly developed Pseudomonas vaccine, CFC-101, is highly effective for the protection from death caused by pseudomonal infections.
【The treatment of pseudomonal infection is a perplexed problem because of its modest susceptibility to most of the major antibiotics. A novel Pseudomonas vaccine(CFC-101) was prepared from the outer membrane protein fractions of several Pseudomonas strains. In this study, we examined CFC-101's effectiveness in both active and passive immunization models. CFC-101 in mice at 0.2 mg/kg, i.p., given three times at two-day intervals, completely prevented the death caused by Pseudomonas aeruginosa. Antibody titer, in accordance with the protective effect in this active immunization, was elevated to its peak level following three consecutive administrations of CFC-101. Thereafter, antibody titer stayed at a constantly high level. Each outer membrane protein fraction from the four CFC-101 producers, exhibited good cross-protective effects in mouse infection models against different Fisher types of P. aeruginosa. In the passive immunization model, 21~336 $\mu\textrm{g}$ /kg of anti-rabbit IgG to CFC-101, when mice being infected with a challenge strain, prevented the Pseudomonhas-induced death up to 60%. Therefore, the preventive effect of CFC-101 was verified in both the active and passive immunization models.】