Meningococcal disease in babies: in 2025, 60 infants under one year old had an invasive meningococcal infection in France, according to Santé publique France, the French national public health agency. It is the most affected age group, with 9.7 cases per 100,000. Among children aged 12 to 35 months, on the other hand, cases are falling, probably an effect of vaccination.
On 28 April 2026, Santé publique France published its annual surveillance report, produced with the National Reference Centre for meningococci. It covers hospitalised cases from 1 January to 31 December 2025. Here is what it says about the very youngest, and what it means for parents.
Meningococcal disease in babies: how many cases in 2025?
In total, 628 invasive meningococcal infections were reported in France in 2025, across all ages. That is 2% more than in 2024. The incidence rate stands at 0.9 cases per 100,000 inhabitants.
These infections are rare but serious. They show up mainly as meningitis or septicaemia. They are notifiable diseases: every case is reported to the regional health agency (agence régionale de santé), which organises protection for close contacts.
Infants under one year old remain the most exposed. The 60 cases recorded in this group in 2025 correspond to 9.7 cases per 100,000 children of that age. Two serogroups, B and W, account for almost all of these cases.
Serogroups in under-ones
- Serogroup B: 31 cases, or 5.0 per 100,000.
- Serogroup W: 22 cases, or 3.55 per 100,000. It accounts for 37% of cases at this age, compared with 33% in 2024.
- Serogroup Y: 6 cases, or 0.97 per 100,000.
- Serogroup C: no cases in under-15s since 2023.
A resurgence since 2022, driven by three serogroups
The number of cases has been rising since 2022, across all ages. Santé publique France attributes this increase to serogroups B, W and Y. Serogroup B is slightly above its pre-Covid-19 pandemic levels. Serogroups W and Y are well above the levels seen previously.
In 2025, among cases with a known serogroup, the breakdown was as follows:
- 279 serogroup B cases, or 46%;
- 178 serogroup W cases, or 29%;
- 143 serogroup Y cases, or 23%;
- 12 cases due to other serogroups or non-capsulated strains.
The year was marked by an exceptional peak in January and February 2025. It coincided with a particularly intense flu epidemic. The monthly number of cases then returned to usual levels, before the seasonal rise in autumn.
A case fatality rate of 13%
The overall case fatality rate of invasive meningococcal infections was 13% in 2025. It reached 21% for serogroup W, which underlines how serious it is.
Are the vaccines mandatory since 2025 already having an effect?
Since 1 January 2025, two vaccinations against meningococci have been mandatory for infants in France. Santé publique France is already seeing encouraging signs in the first children to be vaccinated.
The meningococcal B vaccine
The meningococcal B vaccine was introduced in 2022, first as a recommendation, then made mandatory in 2025. The schedule includes three doses, at 3, 5 and 12 months. Among children aged 12 to 35 months, serogroup B cases have fallen sharply:
- 2 cases in 2025 in 12–23-month-olds, compared with an average of 16 in 2018 and 2019;
- 3 cases in 2025 in 24–35-month-olds, compared with an average of 13 over the same period.
In babies under 6 months, the number of cases remains stable: 24 in 2025, as before 2020. They are too young to have received their first two doses. Between 6 and 11 months, there were 8 cases in 2025, compared with an average of 20 in 2018–2019. Santé publique France points out that the first two doses only provide partial protection.
The meningococcal ACWY vaccine
The ACWY vaccine has replaced the vaccine against meningococcus C alone. It is given at 6 months, with a booster at 12 months. In 2025, 22 serogroup W cases and 6 serogroup Y cases affected infants under one year old. Of these 28 cases, 20 involved babies under 6 months, not yet old enough to be vaccinated.
Among children aged 12 to 35 months, serogroup W cases dropped: 6 in 2025, compared with 15 in 2023 and 16 in 2024. No serogroup Y cases were reported in this age group.
What is vaccine coverage like in infants?
The first estimates were published by Santé publique France in April 2026. They show strong uptake of the first dose, and lower uptake of the full schedule.
- Meningococcal B, first dose by 8 months: 49% for children born in 2022, 75% for 2023, 82% for 2024 and 97% for 2025.
- Meningococcal B, full schedule by 21 months: 35% for 2022, 56% for 2023 and 66% for 2024.
- ACWY, first dose by 8 months: 88% for children born in 2025.
- ACWY, at least one dose by 21 months: 80% for children born in 2024.
The 12-month booster therefore remains the weak point of the schedule. Yet it is the dose that completes the vaccination course.
What this means for parents
Your child’s schedule includes these vaccines at the same appointments as the others. Our article on baby vaccinations in France sets out the whole schedule and the requirements. The HAS (Haute Autorité de santé, France’s national health authority) has also updated the pneumococcal vaccine: see our update on the pneumococcal vaccine for babies.
Catch-up vaccination up to age 5
Catch-up vaccination is recommended up to the 5th birthday for children born before the requirement, that is, children born in 2020, 2021 and 2022. For the ACWY vaccine, Santé publique France states that reimbursement has been in effect since February 2026. The B and ACWY vaccines are reimbursed at 65% by the Assurance Maladie (France’s national health insurance), according to the Santé.fr website.
Winter, a high-risk season
Meningococcal infections are more common in winter. The peak in early 2025 coincided with an intense flu epidemic. The 2026–2027 flu vaccination campaign also covers the people around infants.
If an infant has a fever, a doctor’s advice is essential. Our article on fever in infants explains when to see a doctor and when to call 15 (the French medical emergency number). Red or purplish spots on the skin are among the signs that lead to a meningococcal infection being reported: they call for an immediate emergency call.
Key points
- 60 cases of invasive meningococcal infection in under-ones in 2025, or 9.7 per 100,000: the most affected age group.
- 628 cases across all ages, 2% more than in 2024, with a case fatality rate of 13%.
- Cases are falling in 12–35-month-olds since the B and ACWY vaccines, mandatory since 2025.
- Babies under 6 months, too young to be protected, remain the most affected.
- The full schedule is still incomplete for one child in three: the 12-month booster matters.
Sources
- Santé publique France, “Surveillance des infections invasives à méningocoque en 2025”, surveillance report, national edition, 28 April 2026, in partnership with the CNR (National Reference Centre) for meningococci and Haemophilus influenzae.
- Santé publique France, page “Infections invasives à méningocoque : bilan 2025”, 28 April 2026.
- Santé.fr, “Le vaccin contre méningites et septicémies à méningocoques”, published on 29 April 2025, updated in July 2026.
