 Receiving the recommended vaccinations may not prevent all meningococcal infections, especially from nongroupable N. meningiditis.In 2017, it became clear that eculizumab has caused invasive meningococcal disease despite vaccination, because it interferes with the ability of antimeningococcal antibodies to protect against invasive disease.The drug's labels also carry warnings of severe anemia arising from the destruction of red blood cells as well as severe cases of blood clots forming in small blood vessels.