Vaccine Prevention of Meningococcal Disease: Making Slow Progress

All is not well in the fight against meningococcal disease. Despite the availability, for decades, of meningococcal vaccines, Neisseria meningitidis remains a leading cause of meningitis, sepsis, and other serious infections in both industrialized nations and the developing world [1]. The meningitis belt in sub-Saharan Africa continues to suffer from devastating epidemics of infection due to serogroup A. Unexpectedly, a serogroup W-135 strain has also recently emerged as a cause of epidemic disease in that region, potentially complicating vaccine development and prevention efforts. There are no vaccines for sporadic serogroup B infection because of immunologic cross-reactivity of B polysaccharide with human neural tissue and other related factors. This is truly a vexing problem, because serogroup B strains account for a substantial proportion of meningococcal disease in Europe, the Americas, and elsewhere, and these strains predominate among infants—the group that has both the highest risk of meningococcal disease and the least immunologic maturity. Although a new tetravalent conjugate vaccine was recently licensed in the United States, initial licensure was limited to individuals aged 11–55 years; no licensed product is yet available for the children who are at the highest risk. Clearly, we have a long way to go in preventing meningococcal disease; progress has been slow [2].