flared up arthritis/My thumb and feet pain; Pinched nerve for 6 months in neck/neck pain; This spontaneous case was reported by a patient and describes the occurrence of ARTHRITIS (flared up arthritis/My thumb and feet pain) and NERVE COMPRESSION (Pinched nerve for 6 months in neck/neck pain) in a  patient of an unknown age and gender who received mRNA-1273 (Spikevax) for COVID-19 prophylaxis.     No Medical History information was reported.    On an unknown date, the patient received dose of mRNA-1273 (Spikevax) (unknown route) 1 dosage form. On an unknown date, the patient experienced ARTHRITIS (flared up arthritis/My thumb and feet pain) and NERVE COMPRESSION (Pinched nerve for 6 months in neck/neck pain). At the time of the report, ARTHRITIS (flared up arthritis/My thumb and feet pain) outcome was unknown and NERVE COMPRESSION (Pinched nerve for 6 months in neck/neck pain) had resolved.        The action taken with mRNA-1273 (Spikevax) (Unknown) was unknown.       No concomitant medications were reported.  It was reported that the patient had bad side effects of Moderna Covid vaccine and never had any pain till the patient had shots. After shots it had attacked the patient immune system and flared up arthritis that the patient never had.   It was also reported that the patient was having many hospital bills. The patient thumb, feet and the worst were severe neck pain. The patient also had pinched nerve for 6 months in neck and just had an MRI. Reportedly, no pain till right after Moderna Covid vaccines.  No treatment information was provided by the reporter.  Company comment: This spontaneous case concerns a patient of unknown age and gender with no reported medical history who experienced the unexpected non-serious adverse event of special interest arthritis which occurred at an unknown interval after receiving a dose of mRNA1273. Additional event of nerve compression was also mentioned in the case.The patient experienced flared up arthritis post vaccination with pain in the thumb and feet along with severe neck pain. The patient underwent MRI on an unspecified date which revealed pinched nerve in the neck persistent for 6 months. Further details regarding the clinical course, hospital admission, other diagnostic or imaging test done, concomitant medications and treatment were not provided.  The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.; Sender's Comments: This spontaneous case concerns a patient of unknown age and gender with no reported medical history who experienced the unexpected non-serious adverse event of special interest arthritis which occurred at an unknown interval after receiving a dose of mRNA1273. Additional event of nerve compression was also mentioned in the case.The patient experienced flared up arthritis post vaccination with pain in the thumb and feet along with severe neck pain. The patient underwent MRI on an unspecified date which revealed pinched nerve in the neck persistent for 6 months. Further details regarding the clinical course, hospital admission, other diagnostic or imaging test done, concomitant medications and treatment were not provided.  The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.