Meningitis and other meningococcal infections are rare but serious, sometimes fatal, and can cause severe after-effects. There are several meningococcus groups, each comprising different strains. Group B meningococcus is implicated in 72% of infections. Meningococcal infections generally affect children under the age of 5, especially infants in their first year, and adolescents. Antibiotic treatment is not always sufficient to prevent a fatal outcome or severe after-effects. The death rate averages around 8%, while about 15% of survivors suffer severe after-effects.
The Bexsero° vaccine is the first vaccine available in France having been granted a marketing authorisation against some group B meningococcal infections. During the trials, this vaccine was not evaluated in terms of clinical protection, but according to in vitro studies, it provides protection against 85% of the invasive meningococcal B strains isolated in France in 2007-2008.
The adverse effects are mainly local – redness, hardening and local pain – but also systemic: fever in around 50% of children. But potentially severe adverse effects (Kawasaki syndrome) seemed more frequent in patients vaccinated in the course of clinical trials, and need further investigation, since this syndrome is associated with cardiac complications.
In practice, the harm-benefit balance of the new meningitis B vaccine justifies its use for some people at risk as a result of certain deficiencies and in the event of an epidemic, on condition that the vaccine antigens correspond to the epidemic strain, as well as in the context of clinical research to evaluate the vaccine’s effectiveness and better define the risk of Kawasaki syndrome.
©Prescrire 1 September 2014
"Meningococcal B vaccine: An immunogenic vaccine possibly useful during outbreaks" Prescrire Int 2014; 23 (152): 201-204. (Pdf, subscribers only).