Age: 3.0
Sex: F
Vaccine: FLUX
Symptoms: Acute disseminated encephalomyelitis, Asthenia, Babinski reflex test, Central nervous system lesion, Cerebral disorder
Clinical narrative: Acute Disseminated Encephalomyelitis; became more lethargic/lethargy; fever; headache; multiple episodes of vomiting; some episodes of difficulty speaking; weakness; refused oral intake; drooling; right facial and arm weakness; became more irritable; right facial and arm weakness; had difficulty walking; decreased right nasolabial fold but was able to wrinkle her forehead; several episodes of seizure that persisted even after her other symptoms resolved; non-enhancing lesions in the cerebral hemispheres and brainstem; Initial information received on 29-Oct-2024 via physician regarding an unsolicited valid serious case issued from a literature article:    This case involves a 3-year-old (Case 6) female patient who experienced acute disseminated encephalomyelitis while receiving vaccine Influenza vaccine (Latency: 5 days).  The patient's past medical history, medical treatment(s), vaccination(s) and family history were not provided.   On an unknown date, the patient received a dose of suspect Influenza vaccine produced by unknown manufacturer lot number not reported via unknown route in unknown administration site.   On an unknown date, five days after receiving the vaccine, she developed fever (pyrexia), headache, and multiple episodes of vomiting (vomiting). Over the course of the next week, the patient had some episodes of difficulty speaking (speech disorder), became more lethargic (lethargy), and refused oral intake  (hypophagia). She presented with lethargy, fever, and weakness (asthenia) 2 weeks after receiving the influenza vaccine. On the day before admission, the patient began drooling and became more irritable (irritability). Upon admission, she was afebrile; however, she developed right facial and arm weakness (facial paresis) (muscular weakness) and also had difficulty walking (gait disturbance). On physical examination, the patient was still drooling and irritable. She had a decreased right nasolabial fold but was able to wrinkle her forehead (decreased nasolabial fold). She had a slow and narrow based gait. Her arms were flexed but were able to extend when prompted. Extraocular muscles were intact, tongue was midline, strength and sensation were intact, and deep tendon reflexes were 2+ with a negative Babinski reflex. Initial (magnetic resonance imaging) MRI of the brain revealed numerous amorphous and rounded, slightly expansive, non-enhancing lesions in the cerebral hemispheres and brainstem (Central nervous system lesion). She was treated with high-dose steroids with resolution of her symptoms. During admission, the patient had several episodes of seizure that persisted even after her other symptoms resolved (seizure). Follow-up MRI without contrast performed 1 month after initial presentation showed near resolution of the abnormal signal besides some residual abnormalities in the left occipital lobe.  Seriousness criteria: medically significant and hospitalization. Action taken: not applicable Corrective treatment: high-dose steroids Outcome: Recovering / Resolving for the event acute disseminated encephalomyelitis. Reporter's causality: Related; Sender's Comments: Sanofi company comment on dated 06-NOV-2024: This case involves a 3-year-old female patient who experienced acute disseminated encephalomyelitis while receiving vaccine Influenza vaccine. Based on the limited information received the causal role of VACCINE cannot be excluded due to compatible temporal relationship of ADR to the VACCINE. Further information regarding concurrent condition during vaccination, previous vaccination, tolerance, allergic history, laboratory investigations excluding alternative etiologies for the reported event are needed to fully assess this case. Based upon the reported information, the role of vaccine cannot be assessed completely.