very painful neck/then went into my neck; cannot fully turn my head either left or right since the Moderna booster shot/has taken turns going from right to left side of neck/the pain is in both sides preventing me from turning my head fully to left and right side; pain at the injection site went through my arm; pain at the injection site went through my arm and into my armpit during the first 4 -5 days; pain at the injection site; prolonged muscle aches in the neck on both sides, but mostly the side where vaccine occurred; This spontaneous case was reported by a consumer and describes the occurrence of NECK PAIN (very painful neck/then went into my neck), MUSCULOSKELETAL STIFFNESS (cannot fully turn my head either left or right since the Moderna booster shot/has taken turns going from right to left side of neck/the pain is in both sides preventing me from turning my head fully to left and right side), PAIN IN EXTREMITY (pain at the injection site went through my arm), AXILLARY PAIN (pain at the injection site went through my arm and into my armpit during the first 4 -5 days) and VACCINATION SITE PAIN (pain at the injection site) in a 64-year-old patient of an unknown gender who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     No Medical History information was reported.    On 04-Dec-2021, the patient received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On an unknown date, the patient experienced NECK PAIN (very painful neck/then went into my neck), MUSCULOSKELETAL STIFFNESS (cannot fully turn my head either left or right since the Moderna booster shot/has taken turns going from right to left side of neck/the pain is in both sides preventing me from turning my head fully to left and right side), PAIN IN EXTREMITY (pain at the injection site went through my arm), AXILLARY PAIN (pain at the injection site went through my arm and into my armpit during the first 4 -5 days), VACCINATION SITE PAIN (pain at the injection site) and MYALGIA (prolonged muscle aches in the neck on both sides, but mostly the side where vaccine occurred). At the time of the report, NECK PAIN (very painful neck/then went into my neck) had not resolved and MUSCULOSKELETAL STIFFNESS (cannot fully turn my head either left or right since the Moderna booster shot/has taken turns going from right to left side of neck/the pain is in both sides preventing me from turning my head fully to left and right side), PAIN IN EXTREMITY (pain at the injection site went through my arm), AXILLARY PAIN (pain at the injection site went through my arm and into my armpit during the first 4 -5 days), VACCINATION SITE PAIN (pain at the injection site) and MYALGIA (prolonged muscle aches in the neck on both sides, but mostly the side where vaccine occurred) was resolving.            Concomitant medication of the patient was not reported.   The patient had self-treated with ice and heat and it improved slightly, however the pain persisted and had become quite worrisome to the patient. It had been over a month since the patient received the booster.  The patient had in excellent health other than this persistent neck pain.