Key Points 

• In 2025, 40 cases of invasive meningococcal disease (IMD) were reported in Normandy, representing an incidence of 1.18 per 100,000 inhabitants—the highest rate in France—confirming the resurgence of IIM observed since the end of the COVID-19 pandemic.
• The distribution across the different serogroups was similar to previous years: 22 IIM B (55% of cases with known serogroup), 9 IIM W (23%), and 8 IIM Y (20%).
• The age groups most affected varied by serogroup:
  • IIM B: higher incidence rate among infants and young children aged 1 to 4 years;
  • IIM W and Y: higher incidence rates among infants and the elderly (>75 years).
• No cases of IIM C were reported in 2025. High vaccination coverage among infants against meningococcal C has led to a decrease in the number of cases associated with this serogroup since 2018.