Pseudonomas aeruginosa vaccine (PV) containing predominantly cell-wall protein protective antigens was tested for safety and immunogenicity by immunization of 119 volunteers. The criteria for safety and immunogenicity were the absence of serious post-vaccinal reactions or complications either during immunization or 12 months later. There were mild (19 donors or 15.9%) and moderate (three donors or 2.5%) febrile reactions after immunization and in two volunteers the body temperature increased up to 38-degrees-C, however it decreased to normal values within 24 h. We observed in 43 (36.1%) of volunteers mild and in five (4.2%) moderate local reactions which disappeared within 24 h. Using the ELISA and passive mouse protection test it was shown that PV induces the formation of specific antibodies. A high level of specific antibodies persisted for the 5-month period of observation. The antibody titres increased in 94-97% of volunteers and moreover in 45.6% the antibody titres (the number of ELISA units) increased 2.5-3-fold and more. Anti-P. aeruginosa plasma was used for the treatment of 46 patients with severe forms of P. aeruginosa infection (40 adults and six infants aged up to 2 years) and 87% of the patients recovered.