AFTER-EFFECTS OF INVASIVE MENINGOCOCCAL DISEASES. Invasive meningococcal infections (IMI) still have a mortality rate of 11% in France. Recent nationwide studies have been able to quantify the long-term sequelae among survivors and highlight their diversity. In addition to the immediate effects seen at the end of hospitalization, numerous sequelae can emerge months or even years later. It is currently estimated that 20 to 30 % of survivors will experience at least one sequela, with 9 to 10 % having multiple after-effects. The most common sequelae are neurological (such as epilepsy and severe motor disorders) and psychological (like anxiety). Physical after-effects, such as skin scarring or amputations, while less frequent, often entail significant treatment cost. Cognitive difficulties, academic-learning challenges, and psychological, behavioral, or emotional disorders, are frequently diagnosed late and are probably underestimated. Communication or language problems carry a risk ratio > 20 compared to controls. This wide range of sequelae contributes to the complexity and high cost of care. It shows the importance of obtaining the most accurate possible estimate of IMI's impact and their after-effects, as well as implementing the preventive measures now available.