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): 1.0-1.917,  Meningitis Meningococcal Meningitis Meningococcal Infections Aged 12 to 23 months on the day of the first study visit Participants had received all recommended standard-of-care non-meningococcal vaccinations according to his/her age as per local regulations Informed consent form (ICF) had been signed and dated by the parent/legally acceptable representative Participant and parent/legally acceptable representative were able to attend all scheduled visits and complied with all trial procedures Covered by health insurance if required by local regulations Participants had received any meningococcal vaccine in the second year of life (i.e., from 12 months of age) For in Groups 1 and 2: Participants must not had received any vaccination against meningococcal disease with either a trial vaccine or a licensed meningococcal vaccine (i.e., polyvalent, polysaccharide, or Conjugate meningococcal vaccine containing serogroups A, C, W, Y, B; or any monovalent or bivalent meningococcal vaccine) For in Groups 3 and 4: Participants must had previously received at least 1 dose of licensed monovalent meningococcal C Conjugate (MenC) vaccine during infancy (i.e., before 12 months of age)  Participation in the 4 weeks preceding the trial vaccination or planned participation during the present trial period in another clinical trial investigating a vaccine, drug, medical device, or medical procedure Receipt of any vaccine in the 4 weeks (28 days) preceding the trial vaccination or planned receipt of any vaccine prior to Visit 2 except for influenza vaccination, which may be received at least 2 weeks before or after study investigational vaccines. This exception included monovalent pandemic influenza vaccines and multivalent influenza vaccines Receipt of immune globulins, blood or blood-derived products in the past 3 months For Groups 1 and 2 only: Vaccination against meningococcal disease with either a trial vaccine or a licensed meningococcal vaccine (i.e., polyvalent, polysaccharide, or Conjugate meningococcal vaccine containing serogroups A, C, W, Y, B; or any monovalent or bivalent meningococcal vaccine) For Groups 3 and 4 only: Vaccination against meningococcal disease with either a trial vaccine or a licensed meningococcal vaccine (i.e., polyvalent, polysaccharide, or Conjugate meningococcal vaccine containing serogroups A, C, W, Y, B; or any monovalent B meningococcal vaccine), except licensed monovalent meningococcal C Conjugate (MenC) vaccination received during infancy Known or suspected congenital or acquired immunodeficiency; or receipt of immunosuppressive therapy, such as anti-cancer chemotherapy or radiation therapy, within the preceding 6 months; or long-term systemic corticosteroid therapy (prednisone or equivalent for more than 2 consecutive weeks within the past 3 months) History of meningococcal infection, confirmed either clinically, serologically, or microbiologically At high risk for meningococcal infection during the trial (specifically, but not limited to, participants with persistent complement deficiency, with anatomic or functional asplenia, or participants travelling to countries with high endemic or epidemic disease) Known systemic hypersensitivity to any of the vaccine components, or history of a life-threatening reaction to the vaccines used in the trial or to a vaccine containing any of the same substances Personal history of an Arthus-like reaction after vaccination with a tetanus toxoid-containing vaccine