This spontaneous case was retrieved on 19-Oct-2021 from Vaccine Adverse Event Reporting System (VAERS) (reference number: 1740995-1) with additional information retrieved on 20-Oct-2021 from VAERS (reference number: 1741060-1) (being processed together) reported by other healthcare professional and concerned a 56-year-old male patient.   The patient's concurrent condition included hypertension, contrast dye and shellfish allergy and chronic renal insufficiency. The patient had adrenalectomy secondary to aldosteronoma. The patient's concomitant medications included Baby aspirin (acetylsalicylic acid), Claritin (loratadine), Crestor (rosuvastatin calcium) and Tribenzor (amlodipine besilate, hydrochlorothiazide, olmesartan medoxomil), all for unreported indication.  On 02-Sep-2021, the patient was vaccinated with Flucelvax Quadrivalent (influenza vaccine, subunit influenza virus vaccine polyvalent; route of administration: intramuscular, anatomical location: right arm, dose and indication: not reported). The batch number reported was 309614.  On 03-Sep-2021, one day after administration of Flucelvax Quadrivalent, the patient developed fatigue, low grade fever, myalgia surrounding back, shoulder, elbows, hands, knees, hips and feet, arthralgia, severe am stiffness, difficulty straightening arms and raising arms and difficulty walking.   On an unspecified date in Sep-2021, blood work indicated elevated erythrocyte sedimentation rate (ESR) of 52 and C-reactive protein (CRP) of 21.5.  From 22-Sep-2021 till 27-Sep-2021, the patient was using Medrol (methylprednisolone) as corrective treatment. The patient had abrupt response to Medrol two to three days after taking, pain 80-90% improved. Currently symptoms persist, worse in arm and when sleeping prior to steroids, unable to sleep due to unretractable shoulder and elbow pain.  At the time of initial reporting, the patient had not recovered from all events, except for events of 'c-reactive protein increased' and 'erythrocyte sedimentation rate increased'.   The outcome of the events 'C-reactive protein increased' and 'erythrocyte sedimentation rate increased' was not reported.  The reporter did not provide a causality assessment.  The events were assessed as non-serious.  Company comment: A 56-year-old patient experienced decreased mobility of arms, gait disturbance, insomnia, arm stiffness, arthralgia, myalgia, fatigue, and pyrexia one day after after receiving the suspect product Flucelvax Quadrivalent. The patient also developed increased C-reactive protein and erythrocyte sedimentation rate unknown amount of time after administration. Although therapy with concomitant drugs Crestor and Tribenzor confounds causality, it is assessed as possibly related, based on plausible chronology, except for increased C-reactive protein and erythrocyte sedimentation rate, which is unassessable, due to unclear time relationship.; Sender's Comments: A 56-year-old patient experienced decreased mobility of arms, gait disturbance, insomnia, arm stiffness, arthralgia, myalgia, fatigue, and pyrexia one day after after receiving the suspect product Flucelvax Quadrivalent. The patient also developed increased C-reactive protein and erythrocyte sedimentation rate unknown amount of time after administration. Although therapy with concomitant drugs Crestor and Tribenzor confounds causality, it is assessed as possibly related, based on plausible chronology, except for increased C-reactive protein and erythrocyte sedimentation rate, which is unassessable, due to unclear time relationship.