her muscles hurt a lot; She lost her balance; She noted that her stomach was hurting; she lost her appetite/She didn't eat for approximately 3 weeks; she has been in bed for the past 2 weeks; She started to sweat; She also had diarrhea; she started to feel sick again 2 days later; began talking and hallucinating; She was freezing and there was nothing that could keep her warm for approximately 2 hours; Initial information was received on 25-Apr-2023 regarding an unsolicited valid  serious case received from a consumer/non-healthcare professional (Patient).  This case involves a 69 years old female patient who began talking and hallucinating, she was freezing and there was nothing that could keep her warm for approximately 2 hours, her muscles hurt a lot, she lost her balance, she noted that her stomach was hurting, she lost her appetite/she didn't eat for approximately 3 weeks, she has been in bed for the past 2 weeks, she started to sweat, she also had diarrhea and she started to feel sick again 2 days later after being vaccinated with influenza quadrival A-B high dose HV vaccine [Fluzone high-dose quadrivalent].  The patient's past medical history, medical treatment(s), vaccination(s) and family history were not provided.  Concomitant medications included pneumococcal vaccine conj 20v (CRM197) (Prevnar 20) for Prophylactic vaccination (immunization); and diphtheria vaccine toxoid, pertussis vaccine acellular 3-component, tetanus vaccine toxoid (Boostrix) for Prophylactic vaccinateion (Immunisation).  On 19-Jan-2023, the patient received total dose of suspect INFLUENZA QUADRIVAL A-B HIGH DOSE HV VACCINE (strength: High dose) (lot number, route and expiry date: Unknown) in left upper arm .  On an unknown date the patient developed a serious event of began talking and hallucinating (hallucination) (unknown latency) following the administration of influenza quadrival a-b high dose hv vaccine.   On an unknown date the patient developed a non-serious events of she was freezing and there was nothing that could keep her warm for approximately 2 hours (body temperature decreased), her muscles hurt a lot (myalgia), she lost her balance (balance disorder), she noted that her stomach was hurting (abdominal pain upper), she lost her appetite/she didn't eat for approximately 3 weeks (decreased appetite), she has been in bed for the past 2 weeks (bedridden), she started to sweat (hyperhidrosis), she also had diarrhea (diarrhoea), she started to feel sick again 2 days later (illness) (unknown latency) following the administration of influenza quadrival a-b high dose hv vaccine.  No lab data reported.  Action taken: not applicable.  It was not reported if the patient received a corrective treatment for all the events.  Outcome: Unknown for all the events.  Seriousness criteria: medically significant for the event began talking and hallucinating.; Sender's Comments: Sanofi company comment date 27-Apr-2023: This case involves a 69 years old female patient who began talking and hallucinating, she was freezing and there was nothing that could keep her warm for approximately 2 hours, her muscles hurt a lot, she lost her balance, she noted that her stomach was hurting, she lost her appetite/she didn't eat for approximately 3 weeks, she has been in bed for the past 2 weeks, she started to sweat, she also had diarrhea and she started to feel sick again 2 days later after being vaccinated with influenza quadrival A-B high dose HV vaccine [Fluzone high-dose quadrivalent]. Concomitant medication included pneumococcal vaccine conj 20v (CRM197) (Prevnar 20) and diphtheria vaccine toxoid, pertussis vaccine acellular 3-component, tetanus vaccine toxoid (Boostrix). The causal role of the company suspect vaccine cannot be excluded based on the temporal relevance instead of the time to onset is compatible with the role of the vaccine. However, role of medical history, concomitants cannot be overlooked either. Furthermore, information regarding condition at the time of vaccination, lab data excluding other predisposing etiologies would be needed for complete assessment of the case. Based upon the reported information, the role of an individual vaccine cannot be assessed.