The patient reported the booster caused a relapse; The patient reported the booster caused a relapse, which he described as his "left eye moved" a couple of days after his Covid booster and would not point in the same direction of his right eye and he could not focus and saw double vision.; This spontaneous case was reported by a consumer and describes the occurrence of MULTIPLE SCLEROSIS RELAPSE (The patient reported the booster caused a relapse) in a 63-year-old male patient who received mRNA-1273 BIVALENT .222 (MODERNA COVID-19 VACCINE, BIVALENT (ORIGINAL AND OMICRON BA.4/BA.5)) for COVID-19 prophylaxis. The occurrence of additional non-serious events is detailed below.     The patient's past medical history included Prostatectomy NOS from 2006 to 2008, Eye abnormality, Foot drop and Brain tumor operation. Concurrent medical conditions included Primary progressive multiple sclerosis and Iodine allergy. Concomitant products included SIMVASTATIN, OCRELIZUMAB (OCREVUS), AMITRIPTYLINE HCL, GABAPENTIN, MECLIZINE [MECLOZINE], VITAMIN D3 and TAMSULOSIN HCL for an unknown indication.    On 08-Apr-2023, the patient received sixth dose of mRNA-1273 BIVALENT .222 (MODERNA COVID-19 VACCINE, BIVALENT (ORIGINAL AND OMICRON BA.4/BA.5)) (unknown route) 1 dosage form. In April 2023, the patient experienced MULTIPLE SCLEROSIS RELAPSE (The patient reported the booster caused a relapse) (seriousness criterion medically significant) and DIPLOPIA (The patient reported the booster caused a relapse, which he described as his "left eye moved" a couple of days after his Covid booster and would not point in the same direction of his right eye and he could not focus and saw double vision.). The patient was treated with METHYLPREDNISOLONE SODIUM SUCCINATE (SOLU MEDROL) (intravenous use) at an unspecified dose and frequency. At the time of the report, MULTIPLE SCLEROSIS RELAPSE (The patient reported the booster caused a relapse) and DIPLOPIA (The patient reported the booster caused a relapse, which he described as his "left eye moved" a couple of days after his Covid booster and would not point in the same direction of his right eye and he could not focus and saw double vision.) was resolving.            Concomitant medication included OSTEO BI-FLEX JOINT HEALTH GLUCOSAMINE CHONDROITIN WITH JOINT SHIELD.  Patient received Dose 1 of Covid-19 Moderna vaccine on 16-MAR-2021, Dose 2 of Covid-19 Moderna vaccine on 13-APR-2021. Patient also received Dose 3 (booster dose) of Moderna vaccine on 17-SEP-2021, Dose 4 (booster dose) of Moderna vaccine on 05-APR-2022 and dose 5 (booster dose) of Moderna vaccine on 19-OCT-2022.  Patient reported that his last infusion was on 10-Jul-2023, and approximately 90 days before that, he received a Covid booster (08-Apr-2023). Patient stated that the event was mostly cleared up. Patient further clarified that his eye went back to a place where it was comfortable to see and drive, and was able to do things he had done before. Patient stated that his doctor stated that the eye trouble he had prior to his brain surgery could be from his tumor, not the Covid booster, but the patient reported only two days after his booster was when his eye moved again.   Reporter did not allow further contact  Company Comment: This spontaneous case concerns a 63-year-old male patient, with medical history of primary-progressive multiple sclerosis, eye abnormality, status post brain tumor operation reported, who experienced serious (medically significant) unexpected AESI of Multiple sclerosis relapse that occurred after a dose of mRNA-1273.222 vaccination, which was described as a booster dose and was 6th dose in COVID-19 vaccination schedule. Latency cannot be calculated due to exact event onset date unknown, however it was reported that the event occurred during the same month after vaccination. The event was accompanied by non-serious event of diplopia. Previously the patient was vaccinated with Moderna vaccines (1st, 2nd, 3rd, 4th and 5th dose). It was reported that the patient was treated with ocrelizumab for multiple sclerosis, details on dosing not available for review. Medical history of primary-progressive multiple sclerosis with eye abnormality and status post brain tumor operation could be considered contributory factors to events development. The course of events was reported as the booster caused a relapse, which was described as his "left eye moved" a couple of days after Covid booster. Treatment included intravenous Solu Medrol drip for five days and condition has resolved. No further details on clinical course, tumor brain operation medical history, diagnostic work up and treatment were provided for review. Outcome of the multiple sclerosis relapse was resolving at the time of the report. The benefit-risk relationship of mRNA-1273.222 is not affected by this report.