I can't bend my arm backwards; She couldn't go back to sleep/ this happens every night/ I don't have much sleep; Pain she is still having at her injection site; Arm started hurting every night especially when trying to sleep it is similar to a bad toothache/Arm where she had the shot really bothered/at night it really hurts/had a sore arm for several hours; Like a bad toothache; This spontaneous case was reported by a consumer and describes the occurrence of PAIN IN EXTREMITY (Arm started hurting every night especially when trying to sleep it is similar to a bad toothache/Arm where she had the shot really bothered/at night it really hurts/had a sore arm for several hours), TOOTHACHE (Like a bad toothache), MOBILITY DECREASED (I can't bend my arm backwards), INSOMNIA (She couldn't go back to sleep/ this happens every night/ I don't have much sleep) and VACCINATION SITE PAIN (Pain she is still having at her injection site) in an 81-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 031B21A and 031L20A) for COVID-19 vaccination.     Medical history was not provided.    On 12-Feb-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 12-Mar-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On 12-Mar-2021, the patient experienced PAIN IN EXTREMITY (Arm started hurting every night especially when trying to sleep it is similar to a bad toothache/Arm where she had the shot really bothered/at night it really hurts/had a sore arm for several hours), TOOTHACHE (Like a bad toothache) and VACCINATION SITE PAIN (Pain she is still having at her injection site). On an unknown date, the patient experienced MOBILITY DECREASED (I can't bend my arm backwards) and INSOMNIA (She couldn't go back to sleep/ this happens every night/ I don't have much sleep). The patient was treated with PARACETAMOL (TYLENOL) at a dose of 1 dosage form. At the time of the report, PAIN IN EXTREMITY (Arm started hurting every night especially when trying to sleep it is similar to a bad toothache/Arm where she had the shot really bothered/at night it really hurts/had a sore arm for several hours), TOOTHACHE (Like a bad toothache), MOBILITY DECREASED (I can't bend my arm backwards) and INSOMNIA (She couldn't go back to sleep/ this happens every night/ I don't have much sleep) outcome was unknown and VACCINATION SITE PAIN (Pain she is still having at her injection site) had not resolved.            No concomitant medications were reported.  The patient had an appointment for the booster dose in November.    Patient stated that last night, woke up at 12 o'clock and arm where had the shot really bothered and couldn't go back to sleep. Stated this happens every night, it hurts very much and at night it really hurts.  Patient could not bend arm backwards and added that during the day can do normal work, but it hurts when lays down, and especially at nighttime when everything magnified, has a miserable time. Patient did not have much sleep.  Patient in the morning take Tylenol and during the day can do normal work.   Most recent FOLLOW-UP information incorporated above includes: On 17-Aug-2021: Significant follow up received included treatment medication and added new events.