Vaccination against meningitis, currently compulsory in infants for a single family of bacteria (the meningococcus C strain), will be expanded from the start of 2025 in the face of the rebound in these serious infections, formalizing a new vaccination schedule published Friday April 26 by health authorities.
Vaccination of children under 1 year old against meningococci A, B, W and Y – as well as C – will be compulsory from next year and will be largely reimbursed by Health Insurance, as recommended by the High Health Authority (HAS).
Currently, only meningococcal C vaccination is mandatory for children under 1 year of age; that against meningococcus B is only recommended. From 2025, a single vaccine, called tetravalent, will target A, C, W and Y. This will be Nimenrix from Pfizer, given in two successive doses, at 6 and 12 months. Given separately in three successive doses, at 3, 5 then 12 months, the anti-B vaccine will remain, as today, Bexsero from Pfizer.
An unprecedented number of cases for ten years
In 2023, 560 cases of invasive meningococcal infections were reported, an increase of 72% compared to 2022 and an unprecedented level for ten years, according to a Public Health France bulletin published on April 9. This post-Covid-19 upsurge could be explained by the decline in immunity in the population, less exposed to meningococci during the pandemic, but also by the return of respiratory viruses (in particular influenza), which can promote infections bacterial invasives.
The incidence was highest in children younger than 1 year (56 cases, or 8.2 cases per 100,000 population). It was also high among young adults aged 15 to 24 (101 cases, or 1.2 cases per 100,000 population).
For a long time, meningococci B and C remained in the majority. This is still the case for B. On the other hand, family C has become marginal, clearly behind Y and W, the latter being particularly murderous. Among the 560 cases reported in 2023, the serogroup was characterized for 535 cases: 240 cases of serogroup B (44%), 160 cases of serogroup W (29.4%), 130 cases of serogroup Y (23.9%). , 5 cases of serogroup C (0.9%).
Meningococci are not the only cause of meningitis, a generic term for inflammation of the membranes of the brain or spinal cord. Most of the time, a virus is the cause. But viral meningitis is generally much less serious than that caused by bacteria. The latter, which manifest themselves in particular by a high fever and a stiff neck, kill a patient devastatingly if he is not treated. And, even when treated, mortality remains 10%.
Not all bacterial meningitis is caused by meningococci, but they are easily transmitted from one person to another. They can therefore cause epidemics, which justified the development of vaccines.
