vaccination is expanded as the number of cases increases

From Wednesday, vaccination against meningococci will be expanded in France, in a context of a rebound in infections by these bacteria which cause particularly serious meningitis.

What is meningococcus?

The word “meningitis” is a generic term for inflammation of the membranes of the brain or spinal cord. Most of the time, a virus is the cause. Viral meningitis is generally much less serious than bacterial ones.

Meningococci are a family of bacteria that cause very dangerous and contagious meningitis, mainly in children and adolescents, as well as septicemia. They are commonly found in the throat and nose, and are transmitted through the air or saliva after close contact. The diagnosis is made by a lumbar puncture which allows the presence of the bacteria to be confirmed and identified; Observation with the naked eye allows the doctor to identify viral meningitis (the fluid is clear) or bacterial (the fluid is cloudy or purulent), and in this case to initiate treatment very quickly. Then a thorough analysis of the liquid makes it possible to identify the germs in question and their sensitivity to antibiotics.

Meningitis and septicemia

Meningitis occurs when bacteria infect the meninges or cerebrospinal fluid. They are manifested in particular by high fever and stiff neck, photophobia, vomiting… Be careful, these symptoms are not always present in infants, and the authorities recommend calling 15 if your baby presents with unusual behavior (whining, incessant crying, drowsiness, etc.), refuses to eat, has a gray or mottled complexion, appears dejected and unresponsive.

They kill the patient with lightning speed if they are not treated. And, when they are, mortality remains 10%, not to mention frequent after-effects: amputation, cognitive disorders, deafness, etc.

Meningococcal sepsis is a generalized infection of the blood and organs. The most serious form is purpura fulminans: red or purplish spots appear on the skin, which do not disappear when pressed with a finger. This is a life-threatening emergency.

A rising number of cases

The new recommendations aim « to better protect infants against these serious infections, in response to a worrying resurgence observed in recent years »recalled the Ministry of Health in a press release in December.

This recovery can be explained by the measures taken against the Covid pandemic in 2020 and 2021. Not only have the restrictions reduced the population’s exposure to meningococci, but they have also weighed down vaccination statistics. Faced with these developments, the High Authority for Health updated its vaccination recommendations last March.

In 2023, according to Public Health France, 560 cases of invasive meningococcal infections had been declared, an increase of 72% compared to 2022. According to the latest figures, provided to AFP by the National Reference Center for Meningococci at Institut Pasteur, more than 500 cases have already been recorded between January and November 2024, a slight increase compared to the same period of 2023. As 2023 had already experienced an unprecedented rebound, « This makes 2024 the year with the highest number of cases in twenty years »underlines infectious disease specialist Muhamed-Kheir Taha, a specialist on the subject at Pasteur, to AFP.

Bacteria that evolve

Another development is also pushing to accelerate vaccination: the profile of the bacteria involved has clearly changed.

The main meningococci are in fact separated into large families: A, B, C, W and Y. For a long time, B and C remained largely in the majority, and were until now the only ones concerned by vaccination. B is still in the majority, but C has become marginal, clearly behind Y and W, the latter being particularly deadly.

The growth of these families has been accompanied by an increase in unusual forms of infection (abdominal forms, bacterial pneumonia, arthritis, etc.), which are sometimes more difficult to diagnose.

What is changing in vaccination?

Only anti-meningococcal C vaccination was obligatory for children under 1 year of age, that against B was only recommended. Among older people, vaccine C was recommended up to age 24, only if the person had not received it as planned when they were less than a year old.

From now on, vaccination will become much broader, according to the new schedule effective from January 1.

In infantsvaccination against all strains – A, B, C, W and Y – will be mandatory. One dose of ACWY conjugate vaccine should be given at 6 months, the second at 12 months; vaccination against meningococci B is done at 3 months, 5 months and 12 months.

In adolescentsa booster dose against A, C, W and Y will be recommended between 11 and 14 years of age, even if they received this vaccine at a young age. It is also recommended for 15-24 year olds for catch-up vaccinations. This is not an obligation, but the advantage is that the vaccine will be largely reimbursed by Health Insurance. On the other hand, the anti-B vaccine will remain reserved for the youngest, the High Health Authority having not judged its benefits sufficient beyond two years.

In adultsvaccination is recommended for people with certain diseases, exposed professionals, and when traveling to certain countries.

In case of contact at risk of infectionantibiotic treatment must be taken quickly and can possibly be supplemented by vaccination. Bacterial meningitis is a notifiable disease, and when a case is reported to the health authorities, they must organize the search for and treatment of contact cases.

What vaccines are available?

A single vaccine, called tetravalent, will target A, C, W and Y. In infants, it will be Nimenrix from Pfizer, given in two successive doses, at 6 and 12 months. Some babies are currently between doses. Even if their first dose, given in 2024, was not the tetravalent vaccine, this will be the case for the second in 2025.

The second dose can also be given with the Menquadfi vaccine from Sanofi. For older children, who will only receive a booster dose, it could be Nimenrix, Menquadfi or Menveo from GlaxoSmithKline (GSK).

The anti-B vaccine will remain, as currently, Bexsero from Pfizer.