Immune response of Brazilian children to a Neisseria meningitidis serogroup B outer membrane protein vaccine: comparison with efficacy

Abstract

Since 1986, serogroup B Neisseria meningitidis has caused approximately 80%Yv of the meningococcal disease in Brazil. In 1988, an epidemic caused byN. meningitidis B:4:P1.15 was recognized in the greater Sio Paulo area of Brazil. The Sfio Paulo state government decided to vaccinate children from 3 to 83 months of age with a vaccine consisting of serotype 4 outer membrane protein and group C meningococcal polysaccharide that was produced in Cuba. About 2.7 million children were vaccinated during two immunization campaigns conducted in 1989 and 1990. Because of this, a case-control study was designed to determine vaccine efficacy against group B meningococcal disease. The purpose of our study was to compare the antibody response with the protection from disease estimated from the case-control study. We measured the immune responses of vaccinees by enzyme-linked immunosorbent assay (ELISA), immunoblot, and bactericidal assay. The development of bactericidal antibodies was age dependent and in good agreement with the results of the case-control study. Only 40%o of vaccinees showed fourfold or greater increases in bactericidal antibody titers after vaccination. A poor correlation between antibody levels detected by ELISA and those by bactericidal assay was found. Immunoblot analysis showed that about 50%o of the serum samples with bactericidal titers higher than 1:4 were reactive with class 1 outer membrane protein. We conclude that the bactericidal assay is a good, laboratorybased, functional assay for the study of vaccine immunogenicity and that an effective solution to group B meningococcal disease remains to be demonstrated.

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

“…In contrast to the clear anti-OMP1 antibody response of immunized patients, the same pattern of antibody response in non-immunized patients was not observed. In agreement with these observations, our previous immunoblot studies of antibody re-sponse of vaccinated children showed that OMP1 was the primary antigen recognized by post-vaccination sera with antibody titers higher than 2 [20]. Similar conclusions regarding the immunogenic potential of OMP1 have been reported by several investigators [14,18,24].…”

“…After vaccination, the proportion of children with bactericidal titer v 2 increased to 24.6%, a proportion similar to the one (25%) found in pre-vaccination sera of children aged 4^6 years. ( [20] and unpublished data). Similar antibody response to another OMP vaccine was described by Boslego et al [12] in Chilean children aged 1^4 years.…”

Optimization of vaccine responses in early life: The role of delivery systems and immunomodulators

“…130,131 Its immunogenicity and safety in children was demonstrated in a large vaccination study involving toddlers. 132 Recently, the adjuvant eect of MF-59 was shown to be superior to an alum preparation with regard to the antibody response to Hib and N. meningitidis conjugate vaccines when administered to infant baboons. 133 Several formulations including various combinations of immunomodulators (alum, MPL, QS21) incorporated in various w/o and o/w emulsions have been developed and are progressively reaching the stage of clinical trials.…”

Reducing inequalities with vaccines: New Zealand's MeNZB vaccine initiative to control an epidemic

“…34 Although this is most clearly established for serogroup C disease, it would be surprising if it was different for serogroup B disease. 12,14,35 Immune memory, even if present, as indicated by the height of antibody response following an extra dose after a priming series 31 or after avidity studies, 36 is unlikely to allow a sufficiently rapid response to provide protection. An important delay of about five days has been demonstrated in already primed infants before titre rise after the administration of a booster dose of vaccine.…”