Patient description: The patient is a 23-year-old man who came to the hospital with high blood pressure (175/95 mmHg) and signs of septicemia. He developed respiratory failure requiring mechanical ventilation and renal failure requiring hemodialysis. His blood smear showed microangiopathic hemolytic anemia and thrombocytopenia. His blood tests revealed elevated lactate dehydrogenase and reduced human complement C3 levels with a normal coagulation profile. He was diagnosed with atypical hemolytic uremic syndrome. He was treated with plasma exchange and corticosteroids. He has been previously vaccinated with meningococcal group ACWY conjugate vaccine and meningococcal group B vaccine. The genetic survey revealed ADAMTS13 >10%.

Clinical trial eligibility criteria: eligible ages (years): 2.0-999.0,  Meningococcal Disease Individuals eligible for enrollment in this study were those: 1. Who were of any gender, from the age of 2 years and above at the time of visit 1, and to whom the nature of the study had been described and the parent/legal representative had provided written informed consent (≥2 to <18 years of age) had provided written assent (≥11 to <18 years of age) had provided written informed consent (≥18 years of age onwards). 2. Who the investigator believed that the subject and/or his or her parent/legal representative could and would comply with the requirements of the protocol (e.g., completion of the Diary Card, return for follow-up visit). 3. Who were in good health as determined by medical history physical exam clinical judgment of the investigator 4. Who had a negative urine pregnancy test for female subjects from 11 years of age  Individuals not eligible to be enrolled in the study were those: 1. Who were unwilling or unable to give written informed assent or consent to participate in the study. 2. Who were perceived to be unreliable or unavailable for the duration of the study period. 3. Who had a previous confirmed or suspected disease caused by N meningitidis. 4. Who had household contact with and/or intimate exposure to an individual with culture-proven N meningitidis infection within 60 days prior to enrollment. 5. Who had previously been immunized with a meningococcal vaccine or vaccine containing meningococcal antigen(s) (licensed or investigational). 6. Who were pregnant or breast feeding (female subjects). 7. Who had received any investigational or non-registered product (drug or vaccine) within 28 days prior to enrollment or who expected to receive an investigational drug or vaccine prior to the completion of the study. 8. Who had received any vaccines within 14 days (for inactivated vaccines) or 28 days (for live vaccines) prior to enrollment in this study or who were planning to receive any vaccine within 30 days from the study vaccines. (Exception: Influenza vaccine might be administered up to 15 days prior to study vaccination and at least 15 days after study vaccination). 9. Who had experienced within the 7 days prior to enrollment significant acute infection (for example requiring systemic antibiotic treatment or antiviral therapy) or had experienced fever (defined as body temperature ≥ 38°C) within 3 days prior to enrollment. 10. Who had any serious acute, chronic or progressive disease (e.g., any history of neoplasm, cancer, diabetes, cardiac disease, autoimmune disease, Human immunodeficiency virus (HIV) infection or acquired immunodeficiency syndrome (AIDS), or blood dyscrasias, with signs of cardiac or renal failure or severe malnutrition). Who had epilepsy or any progressive neurological disease or history of Guillain-Barre syndrome. 11. Who had a history of any anaphylaxis, serious vaccine reactions, or allergy to any vaccine components including diphtheria toxin (CRM-197) and latex in the syringe. 12. Who had a known or suspected impairment/alteration of immune function, either congenital or acquired or resulting from (for example) receipt of immunosuppressive therapy within 30 days prior to enrollment (any systemic corticosteroid administered for more than 5 days, or in a daily dose > 1 mg/kg/day prednisone or equivalent during any of 30 days prior to enrollment, or cancer chemotherapy) receipt of immunostimulants receipt of parenteral immunoglobulin preparation, blood products, and/or plasma derivatives within 90 days prior to enrollment and for the full length of the study 13. Who were known to have a bleeding diathesis, or any condition that may be associated with a prolonged bleeding time