Relapse of MS in November of 2021; This spontaneous case was reported by a consumer and describes the occurrence of MULTIPLE SCLEROSIS RELAPSE (Relapse of MS in November of 2021) in an elderly female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 044821A and 007M20A) for COVID-19 vaccination.     Concurrent medical conditions included MS since November 2021.   On 12-Feb-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 12-Mar-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. In November 2021, the patient experienced MULTIPLE SCLEROSIS RELAPSE (Relapse of MS in November of 2021) (seriousness criterion medically significant). At the time of the report, MULTIPLE SCLEROSIS RELAPSE (Relapse of MS in November of 2021) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Magnetic resonance imaging spinal: abnormal (abnormal) New lesion on an MRI scan of spine.         Concomitant medications were not reported.  Patient stated that she had a relapse of Multiple Sclerosis November 2021 and symptoms included new lesion on an MRI scan of spine. Patient contacted their neurologist who recommended patient  to get the booster before the infusion. And Infusion of Rituxan (Rituximab) was occurred on15-Dec-2021 (as per patient, it was an immunosuppressant). Patient stated that infusion was supposed to last for six months and her Neurologist told her to come back 3 months after the infusion (which was March 2022) to have another vaccine.  Treatment information was not provided.  Company comment:This spontaneous case concerns an elderly female patient with a relevant medical history of Multiple sclerosis, who experienced the unexpected, serious Adverse Event of Special Interest of Multiple sclerosis relapse, which occurred approximately 8 months after the second dose of mRNA-1273 vaccine administration. Imaging result showed new lesion on an MRI scan of spine. The patient was treated with an infusion of rituximab (Rituxan). Medical history of Multiple sclerosis could be a confounder for the event. The outcome of the event was reported as unknown. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.   This case was linked to MOD-2022-513122 (Patient Link).   Most recent FOLLOW-UP information incorporated above includes: On 16-Mar-2022: Follow-up received contains no new information.; Sender's Comments: This spontaneous case concerns an elderly female patient with a relevant medical history of Multiple sclerosis, who experienced the unexpected, serious Adverse Event of Special Interest of Multiple sclerosis relapse, which occurred approximately 8 months after the second dose of mRNA-1273 vaccine administration. Imaging result showed new lesion on an MRI scan of spine. The patient was treated with an infusion of rituximab (Rituxan). Medical history of Multiple sclerosis could be a confounder for the event. The outcome of the event was reported as unknown. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.