Guillain-Barré syndrome; subsequent hypercapnic respiratory failure; areflexia; respiratory muscle weakness; generalised weakness; ataxia; acute demyelinating polyneuropathy; abdominal distention; dysphagia; tingling sensation of both hands and feet; Initial unsolicited valid serious case report received from the literature on 02-Jan-2020.   Abstract- The influenza vaccine is recommended annually for every patient older than 6 months. Reported side effects include soreness on injection site, nausea, headache, fever, myalgia, and rarely, Guillain-Barré Syndrome (GBS). GBS is the most common cause of acute flaccid paralysis, with annual incidence of 1.2-3 cases per 100,000 habitants. Even though there is low risk for the development of GBS, it is important to recognize that, annually, one to two cases of GBS are reported per million of patients vaccinated with influenza. A 67-year-old male with past history of hypertension, hyperlipidemia, emphysema, and gastroesophageal reflux disease, presented with complaints of abdominal distention and tingling sensation of both hands and feet since one day prior to admission. Initial physical examination was remarkable for diminished motor strength in upper (3/5) and lower extremities (2/5) accompanied by areflexia. During hospitalization his condition worsened with subsequent development of ataxia as well as generalized weakness. Thirty-six hours after admission, the patient developed respiratory muscle weakness with worsening NIF and subsequent hypercapnic respiratory failure requiring endotracheal intubation. Laboratory evaluation was unremarkable and head CT scan did not suggest acute intracranial event. Further studies, including CSF analysis, failed to reveal albuminocytologic dissociation or any acute infectious process. An electromyography to evaluate for polyneuropathy revealed delayed distal latencies, decreased velocity, and absent F waves suggestive of an acute demyelinating polyneuropathy. Patient had previously denied recent respiratory or gastrointestinal infections, surgery, trauma, HIV, or constitutional symptoms. The only risk factor identified was the administration of influenza vaccination two weeks prior to admission. Despite receiving intravenous immunoglobulins (IVIGs) for 5 days the patient was a failure to wean from mechanical ventilation and a tracheostomy was performed, along with a percutaneous endoscopic gastrostomy due to dysphagia. As a result, two additional courses of IVIGs and one course of plasmapheresis were administered which led to weaning of mechanical ventilation and improvement of motor function. The patient was discharged on physical rehabilitation. GBS is recognized as an acute immunemediated polyneuropathy, usually provoked by a preceding infection. Although rare, development of GBS is a potential complication of the Influenza vaccine. It is of great importance to raise awareness of the diverse side effects associated with current vaccines. This case demonstrates that early identification and acute critical care management of vaccine-related complications can positively influence patient's outcome.  This case involves a 67 year old male patient who developed Guillain-Barre syndrome (Guillain-Barre syndrome), subsequent hypercapnic respiratory failure requiring endotracheal intubation (respiratory failure), ataxia (ataxia), abdominal distention (Abdominal distension) and dysphagia (dysphagia), generalized weakness (Asthenia) while he received vaccine INFLUENZA VACCINE.  Medical history included Emphysema. The concurrent conditions included hypertension, hyperlipidaemia and Gastrooesophageal reflux disease.  On an unknown date (2 weeks prior to admission), the patient received a dose of suspect INFLUENZA VACCINE produced by unknown manufacturer (lot number and other dosing details were not reported).  On an unknown date, the patient developed serious subsequent hypercapnic respiratory failure (respiratory failure) and respiratory muscle weakness with worsening NIF (respiratory muscle weakness), 36 hours following the administration of INFLUENZA VACCINE. These events were assessed as medically significant. The patient was hospitalized for these events.  On an unknown date, the patient developed serious Guillain-Barre syndrome (Guillain-Barre syndrome) with areflexia (areflexia), acute demyelinating polyneuropathy (subacute inflammatory demyelinating polyneuropathy) and tingling sensation of both hands and feet (paraesthesia), generalized weakness (Asthenia) (unknown latency) following the administration of INFLUENZA VACCINE. These events were assessed as medically significant. The patient was hospitalized for these events.  On an unknown date, the patient developed serious ataxia (ataxia), abdominal distention (abdominal distension) and dysphagia (dysphagia) (unknown latency) following the administration of INFLUENZA VACCINE. The patient was hospitalized for these events.  The patient presented with complaints of abdominal distention and tingling sensation of both hands and feet since one day prior to admission.  Relevant laboratory test results included: Laboratory evaluation was unremarkable. On an unknown date, CSF test failed to reveal albuminocytologic dissociation or any acute infectious process. On an unknown date, computerized tomogram of head did not suggest acute intracranial event. On an unknown date, electromyogram shows delayed distal latencies, decreased velocity, and absent F waves suggestive of an acute demyelinating polyneuropathy. Despite receiving intravenous immunoglobulins (IVIGs) for 5 days the patient was a failure to wean from mechanical ventilation and a tracheostomy was performed, along with a percutaneous endoscopic gastrostomy due to dysphagia. As a result, two additional courses of IVIGs and one course of plasmapheresis were administered which led to weaning of mechanical ventilation and improvement of motor function.  It was reported that, although rare, development of GBS is a potential complication of the Influenza vaccine.  Final diagnosis was Guillain-Barre syndrome, ataxia, abdominal distension, respiratory failure and dysphagia.  The patient was treated with IMMUNOGLOBULINS via IV route for 5 days.  At the time of reporting, the event outcome was not reported however there was improvement of motor function.; Sender's Comments: This case concerns a 67 year old patient who presented with Guillain-Barre syndrome, ataxia, abdominal distension, respiratory failure and dysphagia with INFLUENZA VACCINE. The time to onset is compatible for respiratory failure. He had no other risk factor also neuroimaging and CSF were non significant. However, patient's history included emphysema and concurrent conditions included hypertension, hyperlipidaemia and Gastrooesophageal reflux disease. Based upon the reported information, the role of the vaccine is likely.