Breakthrough serogroup Y meningococcal disease in a vaccinated patient with myasthenia gravis receiving ravulizumab: a case report.

We report a case of fulminant invasive meningococcal disease caused by Neisseria meningitidis serogroup Y in a young, immunocompromised adult with myasthenia gravis receiving long-term immunosuppressive therapy including ravulizumab, despite prior meningococcal vaccination. Serogroup Y is increasingly recognized in epidemiological surveillance and may be associated with atypical clinical manifestations, including the uncommon coexistence of meningitis and pulmonary involvement, as observed in this patient. The illness was characterized by rapid progression to septic shock, meningitis, and presumed pleuropneumonia. Diagnosis was confirmed by both blood PCR and culture. This case highlights the increased susceptibility to invasive meningococcal infections in individuals receiving complement-inhibiting therapy and underscores the importance of comprehensive preventive strategies, including a carefully planned and implemented vaccination schedule and careful individualized consideration of antimicrobial prophylaxis.