Vaccine was administered in shoulder and seemed kind of high; shot felt strange going in; can't move or lift arm at all; Nicked nerve; left shoulder much lower than the right; level of pain was a 10 out of 10 a few hours later; A spontaneous report was received from a 40-year-old, female consumer who received Moderna's COVID-19 vaccine (mRNA-1273) and experienced the events, vaccine was administered in should and seemed kind of high, shot felt strange going in, can't move or lift arm at all, nicked nerve, left shoulder much lower than the right, and level of pain was 10 out of 10 a few hours later.    The patient's medical history was not provided. Concomitant product use reported included vitamins, bupropion and trazadone.   On 29 Dec 2020, the patient received their first of two planned doses of mRNA-1273 (Lot # 039K20A) intramuscularly in the left arm for prophylaxis of COVID-19 infection.   On 29 Dec 2020, the patient reported that the vaccine was administered in her left shoulder but that it seemed kind of high.  The patient mentioned to the nurse giving her the vaccine that it felt strange going in and that it did not feel like a normal injection. A few hours later, she stated that her pain level was 10/10.    On 30 Dec 2020, she followed up with her primary physician and was instructed to go to urgent care the next day if she did not feel any better.    On 31 Dec 2020, patient reported that she literally could not move or lift her left arm at all and had to use her right arm to lift it due to the pain.  She also stated that her left shoulder was much lower than the right.  On that same day, she went to an orthopedic urgent care where she was told that the vaccine had potentially nicked a nerve causing the issues in her arm.  However, without an MRI, the urgent care was unable to provide a definitive diagnosis. The patient was prescribed steroids and was told that she could not be referred for an MRI until the nerve became less agitated and inflamed once the steroids took effect, in approximately one week. Treatment for the event included oral steroids.  Action taken with mRNA-1273 in response to the events was not provided.   The outcome of the events, vaccine was administered in should and seemed kind of high, shot felt strange going in, can't move or lift arm at all, nicked nerve, left shoulder much lower than the right, and level of pain was 10 out of 10 a few hours later, was not reported.; Reporter's Comments: This case concerns a 40-year-old female patient who experienced the events of vaccine was administered in should and seemed kind of high, shot felt strange going in, can't move or lift arm at all, nicked nerve, left shoulder much lower than the right, and level of pain was 10 out of 10 a few hours later. The event of shot felt strange going in occurred on the same day when the product was administered, and the events of can't move or lift arm at all, nicked nerve, left shoulder much lower than the right, and level of pain was 10 out of 10 a few hours later occurred within 2 days following administration of the first dose of mRNA-1273, Lot #039K20A. Based on the limited available information, a definitive assessment with regards to a drug: event-causal association cannot be provided at this time. However, due to the temporal association between the onset of the event and the administration of the drug, a causal relationship cannot be excluded. Hence, the events of shot felt strange going in, can't move or lift arm at all, nicked nerve, left shoulder much lower than the right, and level of pain was 10 out of 10 a few hours later are assessed as possibly related to mRNA-1273. The event of vaccine was administered in should and seemed kind of high is a procedural issue and assessed as not applicable.