Bactericidal antibody response to Neisseria meningitidis serogroup B in patients with bacterial meningitis: effect of immunization with an outer membrane protein vaccine

We evaluated the bactericidal antibody response to Neisseria meningitidis s erogroup B in convalescent patients (n = 65) from bacterial meningitis. Pat ients infected with B meningococci were stratified according to their vacci nation status (Cuban BC vaccine) into group 1 (immunized) (n = 12) and grou p 2 (non-immunized) (n = 15). The results suggested that antibody titers gr eater than or equal to 2 (log(2)) indicate a specific immune response to N. meningitidis. In group 1, 64%;, of patients had a significant antibody tit er (greater than or equal to 2) in their acute sera against a B:4:P1.15 str ain, compared to only 21% of group 2 patients. All patients from group 1 wi thout bactericidal antibodies in their acute sera had a significant increas e (at least 2-fold increase in 1og(2) titers) in antibody titers in their c onvalescent sera, in contrast, to only 27% of patients from group 2 (P = 0. 06). Using mutant strains lacking OMP1 or OMP5, it was shown that OMP1 was an important antigen recognized by immunized patients but not by non-immuni zed patients. (C) 2000 Published by Elsevier Science B.V. on behalf of the Federation of European Microbiological Societies.