Case Report: Fulminant meningococcus-meningitis under treatment with ravulizumab despite complete vaccination—a rare but severe complication

The article describes a case of a 41-year-old woman with acetylcholine receptor-positive myasthenia gravis treated with ravulizumab, a complement C5 inhibitor. The patient was fully vaccinated against meningococcus (MenACWY and MenB vaccines) before starting treatment. One month after initiating ravulizumab therapy, she developed nausea, vomiting, and rapidly progressive impaired consciousness. Cerebrospinal fluid analysis confirmed bacterial meningitis with elevated neutrophils, low glucose, and increased lactate. Culture identified Neisseria meningitidis serotype Y. Despite immediate broad-spectrum antibiotic treatment, her condition deteriorated requiring mechanical ventilation. The patient recovered after 18 days of intravenous antibiotics and was switched to rozanolixizumab. The case demonstrates that vaccination does not eliminate the risk of severe meningococcal infection during complement inhibition.