Febrile Seizure; This 13-month-old male subject was enrolled in a study. The subject received the 4th dose of Bexsero vs Placebo (intramuscular, right thigh) on 12-SEP-2019, for prophylaxis. The subject received the 3rd dose of DTPa-HBV-IPV (intramuscular, left thigh) on 08-MAR-2019, for prophylaxis. The subject received the 3rd dose of Hiberix (intramuscular, right thigh) on 08-MAR-2019, for prophylaxis. The subject received the 1st dose of M-M-R II (subcutaneous, right arm) on 12-SEP-2019, for prophylaxis. The subject received the 1st dose of Varivax (subcutaneous, left arm) on 12-SEP-2019, for prophylaxis. Co-suspect products included Rota (Rotarix liquid formulation) for prophylaxis and Prevenar 13 (Non-GSK Comparator) (Prevenar 13) for prophylaxis. On 01-NOV-2019, 50 days after receiving Bexsero vs Placebo, M-M-R II and Varivax and 238 days after receiving DTPa-HBV-IPV and Hiberix, the subject developed severe – grade 3 febrile seizure (Verbatim: Febrile Seizure). Serious criteria included clinically significant/intervention required. The subject was treated with ibuprofen (Children’S Ibuprofen) and paracetamol (Tylenol Infant). The outcome of febrile seizure was resolved on 01-NOV-2019. Relevant Tests: On 02Nov2019, Urine culture was performed. Findings showed “mixed organisms are present indicating probable contamination or colonization not related to infection”. On 02Nov2019, Urinalysis was performed. Results showed “cloudy” appearance-normal would be “clear”. All other tests were within normal units for the urinalysis.. Diagnostic results (reference ranges are provided in parenthesis if available): Body temperature- 01-NOV-2019 102.2 degree F and in NOV-2019 38.8 degree C. The investigator considered that there was no reasonable possibility that the febrile seizure may have been caused by Bexsero vs Placebo, DTPa-HBV-IPV, Hiberix, M-M-R II and Varivax. The company considered that there was no reasonable possibility that the febrile seizure may have been caused by Bexsero vs Placebo, DTPa-HBV-IPV, Hiberix, M-M-R II and Varivax. GSK Receipt Date: 05-NOV-2019 Thirteen month old who was brought to the Emergency Department for an episode of altered mental status. The child was noted to be playful and active in the morning of 01Nov2019 by his grandmother. He was picked up by Mom after her work and Mom noted that the child “went limp”, staring off into space with eyes open, head flopped back and extremities went limp”. Mom noted “no eye movements or convulsions of extremities. No urinary incontinence. No apnea or cyanosis. He was limp for about two minutes then was very sleepy/hard to engage or arouse for some forty to sixty minutes”. Parents noted later the child shivering and having intermittent chills. In the Emergency Department the child had a temperature of 38.8 degree C and pulse of 185. A urine analysis and urine culture were ordered, and obtained the following day on 02Nov2019. The child was given PO Motrin in the Emergency Department on 01Nov2019. The child was discharged on 01Nov2019 to home with a diagnosis of Febrile Seizure. Before discharge he was afebrile, adequately hydrating. The tachycardia was likely related to his fevers. Teaching was discussed regarding antifebrile medications as well as aggressive oral rehydration. The child was discharged in good condition on 01Nov2019. The child continued on around the clock Motrin and Tylenol alternating each medication until 03Nov2019. He was seen for follow-up on 02Nov2019. And was noted that the fever was “likely viral source”. The child had no symptoms of pneumonia, or evidence of urinary tract infection. Spoke to Mom on 04Nov2019, per Mom “He’s back to normal, no fevers, doing well”. Addendum: Mom reported the duration of the seizure to be approximately 2 minutes (17:30). she also reported that the child’s uncle had one febrile seizure when he was a boy. This child was born full term, had a normal delivery with no infections, trauma or complications. Hi APGARS were 8 at 1 minute after birth and 9 at 5 minutes after birth. He was diagnosed with a “Simple febrile seizure”. He had no post history of hypotonic, hyporesponsive episodes or absence seizures. This case contains an event assessed by the investigator as a serious adverse event of special interest (AESI). The Seizure was Witnessed by parents or relatives. Date of first Seizure was 1/Nov/2019 and Time of first Seizure was 17:30. Body temperature (fever) at the time of generalized convulsive seizure was 102.2 degrees Fahrenheit. Duration of seizure in minutes (approximately) was 2 minutes. Number of generalized convulsive seizures was 1. There was no past history of similar events. There was familial history of similar events but the event was not already reported. Type of Seizure was Febrile Seizure with fever, Subject’s mom reported her brother had one febrile seizure. Diagnostic certainty level was Level 1; Witnessed sudden loss of consciousness and generalized, tonic, clonic, tonic-clonic, or atonic motor manifestations Follow up information received on 15-JAN-2025 Summary of changes: General narrative comments updated. The start date and time of event febrile seizure was 1-NOV-2019 17:30 Upon internal review case was updated on 21-JAN-2025 Co-suspect vaccines DTPa-HBV-IPV, Hiberix,,MMR II, Varivax start date updated.; Sender’s Comments: A case of Febrile convulsion, 50 days after receiving 4th dose of Bexsero vs Placebo, 1st dose of M-M-R II and Varivax and Prevnar 13, 238 days after receiving 3rd dose of DTPa-HBV-IPV vaccine and Hiberix and 298 days after Rotarix liquid formulation, in a 13-month-old male subject. Report is inconsistent with causal relation to the vaccine product, considering implausible time to onset and alternative risk factor (family h/o febrile seizure and multiple concomitant vaccines).