Received Jul 1, 2026
| Type | Name | Manufacturer | Dose | Lot | Route / Site |
|---|---|---|---|---|---|
| FLUX | INFLUENZA (SEASONAL) (NO BRAND NAME) | UNKNOWN MANUFACTURER | UNK | No Batch number | — |
Chronic left shoulder pain; Intense aching pain at rest, sharp pain when moving the arm; Fullness in the shoulder" directly over the injection site; The pain continued to worsen over the next 24 hours; Rotator cuff tear- high-grade partial thickness intrasubstance tear of the supraspinatus; Shoulder injury related to vaccine administration; Synovitis of shoulder and Effusion of joint - for moderate glenohumeral (GH) joint effusion with synovitis.; Glenoid labral tear; Glenohumeral osteoarthritis; Osteopenia; Tenosynovitis; Radiating pain; Acromioclavicular joint osteoarthritis; This literature report (initial receipt 16-Jun-2026) concerns an elderly female patient (Case 1) presented to the clinic with chronic left shoulder pain that started immediately after an influenza vaccine (trade name, manufacturer and lot number not reported - to be requested upon follow up). This retrospective case series included patients seen between -Apr-2022 and -Dec-2024 at a private sports medicine clinic. Five consecutive patients met all the inclusion criteria. All had received deltoid intramuscular vaccination within 48 hours of symptom onset. Ultrasound revealed hyperechoic punctated foci within the supraspinatus and/or infraspinatus tendons. All five patients responded to an anesthetic injection into the identified area, confirming the origin of their symptoms, and were successfully treated with a tenotomy, vacuum aspiration, and debridement. She reported the initial symptom was an intense aching pain at rest, sharp pain when moving the arm, and a "fullness in the shoulder" directly over the injection site. She denied having left-sided shoulder pain before the injection. The pain continued to worsen over the next 24 hours and started radiating down to the arm to the elbow. She tried using a sling, lidocaine patches, Tylenol, ibuprofen, ice, and heat, but these measures did not provide long-term relief. Before presenting to our office, she was given an intraarticular corticosteroid (CS) injection 2 weeks after the vaccine administration and was prescribed meloxicam and physical therapy (PT). She did have temporary partial relief with the CS injection, but she was unable to tolerate PT as she felt that this exacerbated her shoulder pain. Despite conservative management, she had continued pain at night and when abducting or internally rotating the arm. Owing to continued pain, she had an Magnetic Resonance Imaging (MRI) of the left shoulder 6 weeks from the vaccine administration, which showed an anterior glenoid labral tear, high-grade partial thickness intrasubstance tear of the supraspinatus, partial-thickness undersurface tear of the subscapularis, a delamination tear at the myotendinous junction of the infraspinatus, moderate acromioclavicular (AC) joint osteoarthritis (OA) with narrowing of the subacromial space, and moderate glenohumeral (GH) joint effusion with synovitis. She had a subsequent intra-articular CS injection, which also provided temporary relief, and was then offered shoulder replacement by her orthopedic surgeon. An outside radiograph showed moderate GH and AC joint OA and generalized osteopenia. On presentation to our office 4 months after the vaccination, a diagnostic ultrasound performed at the initial consult showed a heterogeneic lesion with fiber discontinuity consistent with a partial-thickness interstitial tear of the supraspinatus, biceps tenosynovitis, and focal punctate hyperechoic foci within the supraspinatus in a disorganized pattern. A subsequent MRI, 15 months after the vaccine administration, showed a progressive high-grade undersurface tear of the posterior fibers of the supraspinatus, progressive high-grade articular surface tear of the inferior fibers of the infraspinatus, progressive biceps tendinosis, unchanged tear of the anterior inferior labrum, and moderate to severe GH and AC joint OA. A diagnostic injection was performed into the supraspinatus tendon to confirm the location of pain, and the patient reported an 80% improvement in the pain. The patient was treated with a tenotomy, aspiration, and debridement targeting the punctate hyperechoic foci, and at the 2-week follow-up, the pain had decreased from a preprocedural pain level of 4/10 to 1/10. She was able to increase her activity and return to lifting, and at the 2-month follow-up, she reported a 90% improvement in her pain. At 12 months, she reported no recurrent pain at rest. She still continued to have pain with overhead activity, and a platelet-rich plasma injection (120 mL PurePRP, EmCyte Corporation) was performed to address the associated RC tear with further resolution of symptoms.; Reporter's Comments: Causality: Due to the spontaneous nature of the case, the events are considered related for reporting purposes. Osteopenia could be considered coincidental in nature. Osteoarthritis likely represents underlying degenerative changes. For the remaining events, considering close temporal relationship (onset of left shoulder pain immediately after an influenza vaccine). Arthralgia, Pain in extremity, Injection site swelling, Pain, Rotator cuff syndrome, Synovitis, Tenosynovitis and Cartilage injury are more plausibly explained by underlying Shoulder injury related to vaccine administration.
Comments: None