Age: 8.0
Sex: M
Vaccine: FLU4
Symptoms: Disorientation, Dizziness, Influenza virus test negative, Lethargy, Pallor
Clinical narrative: after 2 to 3 minutes of administration had tonic posturing; very disoriented; after 2 to 3 minutes of administration became lethargic; after 2 to 3 minutes of administration very pale; had tinnitus; blurred vision; began feeling dizzy; emesis; Initial information received on 07-Feb-2024 regarding an unsolicited valid serious case received from a physician.  This case involves 8-year-old male patient who after 2 to 3 minutes of administration had tonic posturing, very disoriented, became lethargic, very pale, had tinnitus, blurred vision, began feeling dizzy and emesis after receiving influenza quadrival A-B vaccine [Fluzone QIV].  The patient's past medical history, medical treatment(s), vaccination(s) and family history were not provided. Concomitant: No other vaccines.   On 13-Nov-2023, the patient received 0.5 mL dose of suspect influenza quadrival A-B vaccine, Suspension for injection (Frequency: once; Strength: standard) (lot: U8230AA; expiry date: 30-Jun-2024) via intramuscular route in unknown administration site (but physician stated that it is in the upper extremity) for prophylactic vaccination (immunization).  On 13-Nov-2023 the patient had after 2 to 3 minutes of administration had tonic posturing (tonic posturing), very disoriented (disorientation), after 2 to 3 minutes of administration became lethargic (lethargy), after 2 to 3 minutes of administration very pale (pallor), had tinnitus (tinnitus), blurred vision (vision blurred), began feeling dizzy (dizziness) and emesis (vomiting) (latency: same day) following the administration of influenza quadrival A-B vaccine.   Reportedly, two brothers received their Flu vaccines before including FLUZONE QIV and there are no problems with it. But after 2 to 3 minutes after receiving the vaccine on 13NOV2023, they began feeling dizzy, had tinnitus, blurred vision, emesis. One of the siblings has a tonic posturing which is almost like a seizure type of thing. They did feel better afterwards and they did not go to the hospital. When reporter saw them the day after administration of FLUZONE QIV NP, one of them looks fine while the other one looks very sluggish. This patient experienced more pronounced reaction. After 2 to 3 minutes of administration, he became lethargic, very pale, and had tonic posturing. He was laid to ground. There is no seizure activity and no vomiting, but he is very disoriented. Both of the patients were able to go home that night after several hours. When he woke up, he was still lethargic and pale even when they met the pediatrician the afternoon. They did the Flu titer test also on 28DEC2023 and he had no response to either Flu A and B.  Relevant laboratory test results included: Viral titre - On 28-Dec-2023: [had no response to either Flu A and B]  Action taken was not applicable.  No corrective treatment was received for the events.  At time of reporting, the outcome was Unknown for the event very disoriented, was Unknown for the event after 2 to 3 minutes of administration had tonic posturing, was Not Recovered / Not Resolved for the event after 2 to 3 minutes of administration became lethargic, was Not Recovered / Not Resolved for the event after 2 to 3 minutes of administration very pale, was Recovering / Resolving for the event began feeling dizzy, was Recovering / Resolving for the event had tinnitus, was Recovering / Resolving for the event blurred vision and was Recovering / Resolving for the event emesis.  Seriousness Criteria: The event tonic posturing was assessed as medically significant.; Sender's Comments: Sanofi Company Comment dated 12-Feb-2024: This case involves 8-year-old male patient who after 2 to 3 minutes of administration had tonic posturing, very disoriented, became lethargic, very pale, had tinnitus, blurred vision, began feeling dizzy and emesis after receiving influenza quadrival A-B vaccine [Fluzone QIV]. Based upon the reported information, the role of the vaccine cannot be assessed. However, lack of information regarding past medical history, treatment(s), family history precludes comprehensive case assessment.