convulsive tonic seizure / fell flat to the ground/started convulsing/ eyes rolled back/up in the top of his head,/neck / arched back/she thought he died; his heart may have stopped beating briefly. /brief cardiac arrest/ she thought he died; stopped breathing/ she thought he died; body went stiff; Fell flat on the ground; eyes rolled back/up in the top of his head; neck was arched back in a grotesque manor; has no recollection of the seizure event.; very, very sore/ arm soreness (at the injection site); This case was reported by a consumer via call center representative and described the occurrence of tonic convulsion in a 18-year-old male patient who received Men B NVS (Bexsero) (batch number ABXB05AA, expiry date unknown) for prophylaxis.   Co-suspect products included meningococcal B recom vaccine + aloh + omv pre-filled syringe device (Bexsero Pre-Filled Syringe Device) injection syringe for prophylaxis and TUBERCULIN for prophylaxis.   On 16th July 2021, the patient received the 1st dose of Bexsero (intramuscular), Bexsero Pre-Filled Syringe Device and TUBERCULIN. In July 2021, less than 2 weeks after receiving Bexsero and Bexsero Pre-Filled Syringe Device, the patient experienced injection site pain. On 16th July 2021, the patient experienced tonic convulsion (serious criteria GSK medically significant and life threatening), cardiac arrest (serious criteria GSK medically significant and life threatening), breathing arrested (serious criteria GSK medically significant and life threatening), stiffness (serious criteria life threatening), fall (serious criteria life threatening), eye rolling (serious criteria life threatening), neck discomfort (serious criteria life threatening) and memory impairment. Bexsero was discontinued. On an unknown date, the outcome of the tonic convulsion, cardiac arrest, breathing arrested, stiffness, fall, eye rolling, neck discomfort and injection site pain were recovered/resolved and the outcome of the memory impairment was unknown.   The reporter considered the tonic convulsion, cardiac arrest, breathing arrested, stiffness, fall, eye rolling, neck discomfort, injection site pain and memory impairment to be related to Bexsero and Bexsero Pre-Filled Syringe Device.   This report is made by GSK without prejudice and does not imply any admission or liability for the incident or its consequences.  Additional details were provided as follows: The reporter was the patient's mother. The patient son was not nervous prior to the shot because he wanted to get the shot. He had no fever and never had a seizure before.  The patient received Bexsero in the left upper arm.  The patient's mother believed, it was given intramuscularly because his arm was very, very sore for days.  Eventually the arm soreness at the injection site resolved. The patient's mother stated that, she was at the doctor's office when the Bexsero was given and she witnessed, the patient had a convulsive tonic seizure immediately, less than 15 minutes after the injection.    She said, the patient was leaning on a desk and then he involuntarily fell flat to the ground and started convulsing.   His eyes rolled back/up in the top of his head; his neck was arched back in a grotesque manor.  She said it was horrific to watch his body react so negatively to the vaccine.  She thought he died because his body went stiff, he stopped breathing and she was concerned that his heart might have stopped beating briefly.  She wondered if he had a brief cardiac arrest.   She said he did not simply faint.   The seizure was brief, barely minutes, and by the time the doctor came back into the room it was over, but her son was laying still on the floor in an unnaturally symmetrical way, arms and legs apart and even.  She stated that, the patient went stiff again at the end of the event.  The patient did not wet his pants.   After the event was over, the doctor's office staffs did check his vitals and also did a concussion test and the patient was okay.  The patient's mother stated that, the patient had no recollection of the seizure event.  He did not remember his mom screaming for help.  He only remembered leaning on the desk and then getting up off the floor.  He was on the floor and the desk was next to him fortunately there was nothing for him to hit his head on.  The patient's mother said, she had an appointment to take her son to a cardiologist and a neurologist and that she had reported this to VAERS and that she was going to get a lawyer.   She stated he would not be getting Bexsero shot number 2. It was unknown if the reporter considered the tonic convulsion, cardiac arrest, breathing arrested, stiffness, fall, eye rolling, neck discomfort, injection site pain and memory impairment to be related to Tuberculin. The reporter consented to follow up.; Sender's Comments:  US-GLAXOSMITHKLINE-US2021160395:Same reporter