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Meningococcal meningitis type B: definition
Meningitis is infections of the meninges, the membranes that surround the brain and spinal cord. They can be linked to a virus (this is called viral meningitis), a bacterium (bacterial meningitis) or a parasite.
The most famous and serious meningitis are meningococcal meningitis, the bacteria Neisseria meningitidis, of which there are several types, or “serogroups”. These include serogroups A, B, C, W, X and Y.
In France, meningococcal infections are mainly due to meningococci of serogroups B and C, and mainly concern children under five, adolescents or more rarely young adults.
Meningococcal meningitis B: what symptoms, what treatments?
Meningitis is usually associated with an infectious syndrome, with fever, severe headache and vomiting, a so-called “meningeal” syndrome, characterized by stiff neck, lethargy, sensitivity to light (photophobia), disturbance of consciousness, coma or seizure.
Note that in infants under 12 months, it can be particularly difficult to observe these symptoms, because they are often more discreet or confused with other pathologies (gastroesophageal reflux, classic ENT disorders, etc.).
A strong fevermust therefore urge parents to consult urgently, especially if it is accompanied by intense and incessant crying, a lethargic state, unusual behavior of the baby.
Note also that the sudden appearance of a purpura fulminans, that is, red bleeding spots under the skin, is a medical emergency and a criterion for the severity of meningococcal infection. It requires emergency hospitalization.
The diagnosis of bacterial meningitis is generally made after clinical observation, and confirmed by a lumbar puncture. It happens that antibiotic treatment against meningococcus is administered before the results of the lumbar puncture analysis, to save time on the disease.
Even managed in time, bacterial meningitis can cause brain damage, hearing loss or learning disabilities in 10-20% of survivors.
Meningitis transmission: how do you catch meningococcus B?
Meningococci are transmitted by close direct or indirect contact with nasopharyngeal secretions, in other words saliva and droplets and postilions projected during episodes of coughing or sneezing. The exchange of toys put in the mouth between toddlers is therefore particularly conducive to the spread of these bacteria.
Some individuals are healthy carriers, that is, they are carriers of the bacteria without having symptoms of meningococcal meningitis.
La incubation period between meningococcal infection and the onset of meningitis symptoms varies from 2 to 10 days approximately. On its website, the World Health Organization (WHO) specifies that the transmission of the bacterium Neisseria meningitidis responsible for bacterial meningitis is “favored by promiscuity“(In particular the community, editor’s note) and”large population displacements»Such as cultural and religious events.
Everything about the Bexsero vaccine for prevention of type B meningococcus
The good news about meningococcal meningitis Neisseria meningitidis serogroup B is that there is a vaccine. Named Bexsero, it obtained a European marketing authorization on January 14, 2013, and has been available in France since 2014.
Le Bexsero vaccine against meningococcal meningitis B is only recommended and reimbursed in certain specific situations, especially in fragile people at risk or in an epidemic situation.
Bexsero vaccine: dosage, method of administration and composition
The Bexsero vaccine is made up of antigens, that is to say pieces of the bacteria (proteins and vesicles of the outer membrane) which are recognized by antibodies or cells of the immune system. Aluminum hydroxide as well as several excipients (sodium salt or chloride, and sugar in the form of sucrose in particular) are also included in the composition of the Bexsero vaccine.
The usual dose of Bexsero vaccine is quite complex and varies depending on the age of the person to be vaccinated, but always includes a primary vaccination course (2 to 3 doses one or two months apart) and a booster, especially if there is a continued risk of exposure to meningococcal serogroup B infection.
Bexsero vaccine is given by deep intramuscular injection, preferably in the thigh in infants, or in the upper arm in children and adults.
Possible side effects of the Bexsero vaccine include injection site reactions (pain, redness, swelling or increased tenderness). In infants and children under 10 years of age, the most common side effects, besides injection site reactions, include: fever, irritability, crying, abdominal disorders (diarrhea, vomiting) and eating disorders (including loss of appetite) . In older children and adults, the most common side effects, besides injection site reactions, are headache, nausea and muscle pain.
Is the Bexsero meningococcal B vaccine compulsory for babies?
The Bexsero vaccine is not, for the time being, part of the compulsory vaccines in France, unlike other countries, including the United Kingdom, which has taken the position of making this vaccination compulsory for all infants.
In its opinion of October 2013 following the marketing of the Bexsero vaccine from Novartis, the High Council of Public Health considered that there was not enough information to recommend the use of this vaccine in the context of of a prevention strategy for meningococcal B infections in the general population in France. This decision stems in particular from the fact that the immune protection conferred by the Bexsero vaccine would be limited to 6-12 months after a complete vaccination, and that the vaccination schedule with several injections and boosters was too difficult to integrate into the current vaccination schedule, d ‘especially since Bexsero should ideally be injected separately from other vaccines.
When is meningococcal B vaccination recommended?
Currently, vaccination with the Bexsero vaccine is recommended from the age of 2 months only:
- in people at high risk of contracting an invasive meningococcal infection (personnel from research laboratories working specifically on meningococcus, people with terminal complement fraction deficiency, carriers of a properdin deficiency, or who have received a transplant of hematopoietic stem cells, i.e. stem cells that produce blood cells);
- in populations in epidemic situations or in the case of “clusters of cases”, in particular when at least two cases in less than four weeks have been identified within a community or the same social group.
Meningococcal B vaccine: what price and what reimbursement?
Apart from the indications detailed above, the administration of the Bexsero vaccine is not covered by Social Security. However, it can be partially reimbursed by certain complementary health insurance.
The current price of the Bexsero vaccine is 88,43 euros, reimbursable at 65% in cases where vaccination is recommended.
sources:
- https://www.pasteur.fr/fr/centre-medical/fiches-maladies/meningites-meningocoques
- https://www.has-sante.fr/jcms/p_3066921/fr/recommandation-vaccinale-contre-les-infections-invasives-a-meningocoque-b-place-du-vaccin-bexsero-feuille-de-route