Neisseria meningitidis B vaccines: recent advances and possible immunization policies

Abstract

Since the development of the first-generation vaccines based on outer membrane vesicles (OMV), which were able to contain strain-specific epidemics, but were not suitable for universal use, enormous steps forward in the prevention of Neisseria meningitidis B have been made. The first multicomponent vaccine, Bexsero^®, has recently been authorized for use; other vaccines, bivalent rLP2086 and next-generation OMV vaccines, are under development. The new vaccines may substantially contribute to reducing invasive bacterial infections as they could cover most Neisseria meningitidis B strains. Moreover, other potentially effective serogroup B vaccine candidates are being studied in preclinical settings. It is therefore appropriate to review what has recently been achieved in the prevention of disease caused by serogroup B.

Keywords::

• Bexsero^®
• meningococcal B vaccines
• meningococcus B
• Neisseria meningitidis
• OMV vaccines
• rLP2086
• vaccination

Acknowledgements

The authors thank B Patrick for revising the manuscript.

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending or royalties.

No writing assistance was utilized in the production of this manuscript.

Key issues

• Since the introduction of serogroup C conjugate vaccines into various national immunization programs, the B serogroup of Neisseria meningitidis has become predominant in several areas, such as Europe, Australia and Canada.

• The first-generation vaccines based on outer membrane vesicles were found not to be suitable for universal use because of their limited strain coverage and often scant immune response in young children.

• After the successful results of Phase I–III clinical trials, a multicomponent serogroup B vaccine, Bexsero^®, has recently been authorized by the EMA and the Australian Therapeutic Goods Administration for use in humans aged >2 months.

• Although Bexsero has acceptable safety and tolerability profiles, increased reactogenicity has been observed on concomitant administration with routine immunizations; this may require additional interventions on vaccination risk communication.

• Other vaccines, such as the bivalent rLP2086 and the next-generation detergent-free outer membrane vesicles vaccines, are under development.

• Potential candidate vaccine antigens, such as ZnuD and Omp85 have been discovered and are being tested in preclinical settings; such antigens are of particular interest in view of the fact that some antigens included in the new vaccines, especially factor H binding protein, have been shown not to be essential to meningococcal pathogenesis.

• The new vaccines have a potential, at least in Europe and Canada, to protect against the majority of circulating Neisseria meningitidis B strains.

• Since most capsular strains of the different serogroups can express antigens present in the new vaccines, it is plausible that these may also prevent disease caused by strains other than B strains, as has been demonstrated for serogroups C and X.

• Although the new meningococcal B vaccines are potentially cost-effective, their cost–effectiveness is markedly affected by disease incidence, which varies greatly among countries.