Shoulder pain is a common side-effect after any vaccination, particularly after mRNA vaccine, but these are usually mild and self-limiting after a few days. Many report pain, redness, and swelling around the injection site, as well as headache, fever, fatigue and muscle pain. Shoulder injury related to vaccine administration has been reported following injection, possibly leading to subacromial - subdeltoid bursitis, adhesive capsulitis and rotator cuff tendinitis.
Those that experience shoulder pain often report an injection site that is delivered too high or low in the arm, and inadvertently inflames local tissue in the shoulder. The pain is often described as being directly related to vaccination, usually 48 hours later, with constant pain and stiffness in the shoulder. Pain can persist at night, with exertion, and at rest, and can lead to disability.
Treatment can involve the use of ice packs, manual therapy or corticosteroid injection to reduce inflammation.