The present invention relates to a new use of a vaccine comprising a fusion protein that comprises the Pseudomonas aeruginosa outer membrane protein I (OprI or OMPI) which is fused with its amino terminal end to the carboxy-terminal end of a carboxy-terminal portion of the Pseudomonas aeruginosa outer membrane protein F (OprF or OMPF), as well as to a new use of a monoclonal or polyclonal antibody against this fusion protein or a pharmaceutical composition thereof.
