Condition worsening in content of chronic inflammatory demyelinating polyneuritis; Condition worsening in content of chronic inflammatory demyelinating polyneuritis; Blood return in tubing; Shortness of breath/ SOB with activity; Hoarse; Headache; Feeling ill; Feverish (no fever though); This spontaneous case was received on 15-Oct-2020 from a other health professional and concerned a 64-year-old, male patient.  The patient's concurrent conditions included chronic inflammatory demyelinating polyneuritis and multiple myeloma for which he was enrolled in cancer trial treatment. The patient's concomitant medications included Hizentra (immunoglobulin g human) for chronic inflammatory demyelinating polyneuritis and dexamethasone for multiple myeloma.  On 04-Sep-2020, the patient was vaccinated with influenza virus vaccine polyvalent [brand not specified, indication, dose, route of administration, anatomical location: not reported). The batch number was not reported.   On the same day, after receiving influenza virus vaccine polyvalent, the patient experienced shortness of breath (SOB) with activity.  On unspecified date in Sep-2020, reported as just after the influenza virus vaccine polyvalent was given, the patient was feeling ill. He felt, feverish (without fever) and hoarse. Also the patient developed headache.  On unspecified date, the patient's condition was worsening in content of chronic inflammatory demyelinating polyneuritis. He noticed his condition worsening since discontinuing dexamethasone, so he felt that the steroid with the Hizentra (immunoglobulin g human) was helping. Also, the patient received infusion and that some blood returned in the tubing. The patient did not receive any corrective treatment for the events or had any laboratory tests.  On 09-Sep-2020, the patient recovered from the SOB.  On unspecified date in Sep-2020, the patient recovered from the events of headache and 'infusion site extravasation'.  At the time of initial reporting on 15-Oct-2020, the patient did not recover from the event of 'chronic inflammatory demyelinating polyneuropathy'.  The outcome for the events of 'hoarseness', 'illness' and feverish were not reported.  The reporter assessed the events of shortness of breath, 'hoarseness', 'illness' and feverish to be related to influenza virus vaccine polyvalent and for other events did not reported causality assessment. The reported stated that alternative cause/etiology was flu vaccine received given just prior to feeling ill- SOB with activity, feverish (without fever)and hoarse. The reporter did not provide a causality assessment for other events.  The event of condition worsening in content of chronic inflammatory demyelinating polyneuritis was considered serious due to medically significance by a physician within Seqirus's Department.  Company comment: Aggravation of chronic inflammatory demyelinating polyradiculoneuropathy, dyspnoea, dysphonia, headache, ill-defined disorder, pyrexia and infusion site extravasation were associated with the use of the suspect product influenza virus vaccine polyvalent. Chronology seems suggestive only for dyspnoea while for other seems unclarified. The patient's concurrent conditions included chronic inflammatory demyelinating polyneuritis and multiple myeloma for which he was enrolled in cancer trial treatment and concomitant medications included Hizentra (immunoglobulin g human) for chronic inflammatory demyelinating polyneuritis and dexamethasone for multiple myeloma. After discontinuation of these concomitant drugs aggravation of the main illness started to emerge making causality unrelated to vaccine and more likely related to cessation of supportive therapy for this immunological illness. All other reported events can be a result of the patient main illness, making causality also unrelated to the vaccine. Infusion site extravasation is not related to the vaccine.; Reporter's Comments: The reported stated that alternative cause/etiology was flu vaccine received given just prior to feeling ill- SOB with activity, feverish (without fever) and hoarse.; Sender's Comments: Aggravation of chronic inflammatory demyelinating polyradiculoneuropathy, dyspnoea, dysphonia, headache, ill-defined disorder, pyrexia and infusion site extravasation were associated with the use of the suspect product influenza virus vaccine polyvalent. Chronology seems suggestive only for dyspnoea while for other seems unclarified. The patient's concurrent conditions included chronic inflammatory demyelinating polyneuritis and multiple myeloma for which he was enrolled in cancer trial treatment and concomitant medications included Hizentra (immunoglobulin g human) for chronic inflammatory demyelinating polyneuritis and dexamethasone for multiple myeloma. After discontinuation of these concomitant drugs aggravation of the main illness started to emerge making causality unrelated to vaccine and more likely related to cessation of supportive therapy for this immunological illness. All other reported events can be a result of the patient main illness, making causality also unrelated to the vaccine. Infusion site extravasation is not related to the vaccine.