Sex: M
Vaccine: FLUX, FLUX
Symptoms: Respiratory failure
Clinical narrative: Guillain-Barre syndrome; generalized weakness; dyspnea; hypoxemia; hypotensive; right-leaning posture; repetitive speech; altered mentation; acute hypercapnic respiratory failure; hypercapnia; Initial information received on 17-Jun-2024 via Healthcare Professional regarding an unsolicited valid serious case issued from a literature article:     This case involves a 79-year-old male patient who experienced Guillain-Barre syndrome and acute hypercapnic respiratory failure while receiving vaccine Influenza vaccine (Latency: 2 weeks).  The patient's past medical treatment(s), vaccination(s) and family history were not provided.  Patient with a history of End-Stage Renal Disease (ESRD) on dialysis, diabetes mellitus, hypertension, and atrial fibrillation.   On an unknown date, the patient received high dose of suspect Influenza vaccine produced by unknown manufacturer lot number not reported via unknown route in unknown administration site.  On an unknown date, 2 weeks later, patient presented to the (Emergency department) ED with generalized weakness (asthenia) and dyspnea (dyspnoea). The physical exam showed no neurological deficits but showed hypoxemia (hypoxia) with an oxygen saturation of 88% on room air. Chest x-ray demonstrated a right-sided pleural effusion with pulmonary vascular congestion. The following day, he became hypotensive (hypotension) at 79/50 mmHg and demonstrated right-leaning posture (posture abnormal), repetitive speech, and altered mentation (altered state of consciousness), prompting a call for a code stroke. He had an National Institutes of Health Stroke Scale (NIHSS) Score of 4 and was transferred promptly to the (Intensive care unit) ICU for airway protection. Initial arterial blood gas (ABG) showed severe acute hypercapnic respiratory failure (respiratory failure) with pH 6.99 and partial pressure of carbon dioxide (PCO2) > 125 mmHg. Within a few hours, post-intubation ABG revealed significant improvement in pH 7.45 and pCO2 35 mmHg. Additionally, CT (computed tomography) and MRI (magnetic resonance imaging) brain scans showed no acute intracranial abnormality. The rapid deterioration and the extent of hypercapnia raised concerns for neurological differentials, especially with the patient requiring minimal ventilatory support. After a thorough investigation, additional information obtained included a history of recent hypotensive episodes during dialysis sessions over the past week and a high-dose flu vaccine administered two weeks before symptom onset. A follow-up lumbar puncture revealed albuminocytologic dissociation. The patient was subsequently treated with a 5-day Intravenous immunoglobulin (IVIG) course and extubated successfully.   Author stated that: Guillain-Barre syndrome (GBS) is a rare and severe immune-mediated neurological disorder that affects the peripheral nervous system. It is characterized by demyelinating neuropathy that can rapidly progress, over a few days, to paralysis or even death. While GBS is often associated with infections, there has been a temporal link post-vaccination with GBS pathogenesis. The extent of this association remains a subject of ongoing investigation and review. However, this case highlights the importance of considering GBS as a differential for rapid onset of respiratory failure in recently vaccinated individuals, particularly in elderly patients with no recent infections. In this case, acute hypercapnic respiratory failure in a recently vaccinated, elderly patient prompted a broader neurological differential, leading to a diagnosis of GBS. Although the link between GBS and vaccination remains a subject of study, the case serves as a pertinent reminder for clinicians to consider GBS in similar scenarios. Prompt diagnosis via lumbar puncture and timely treatment with IVIG led to successful patient outcomes, emphasizing the need for diagnostic vigilance.  Seriousness criteria: medically significant for both events. Action taken: not applicable Corrective treatment: IVIG and intubation for both events. Outcome: Recovered / Resolved for both events. Reporter's causality: Related; Sender's Comments: Sanofi company comment on dated 24-JUN-2024: This case involves a 79-year-old male patient who experienced Guillain-Barre syndrome and acute hypercapnic respiratory failure 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, 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.