Encephalitis; She is agile but walks with the aid of a cane and a walker.She cannot currently drive; This spontaneous case was reported by a patient and describes the occurrence of ENCEPHALITIS (Encephalitis) in a 78-year-old female patient who received mRNA-1273 BIVALENT .222 (MODERNA COVID-19 VACCINE, BIVALENT (ORIGINAL AND OMICRON BA.4/BA.5)) (batch no. 043H22A) for COVID-19 prophylaxis. The occurrence of additional non-serious events is detailed below.    Co-suspect products included non-company products LEVOTHYROXINE for an unknown indication, FENOFIBRATE for an unknown indication, PANTOPRAZOLE for an unknown indication, OMEPRAZOLE (PROTONIX [OMEPRAZOLE]) for an unknown indication, RIVAROXABAN (XARELTO) for an unknown indication, ALLOPURINOL for an unknown indication, FULVESTRANT for an unknown indication, MAGNESIUM (MG [MAGNESIUM]) for an unknown indication and LOPERAMIDE for an unknown indication.    The patient's past medical history included Neuropathy and Physical therapy. Concurrent medical conditions included Peritoneal carcinomatosis (stage 4 given 4 months t0 live diagnosed 17 years ago 2005) since 2005, Ovarian cancer (stage 4 given 4 months t0 live diagnosed 17 years ago 2005) since 2005 and Non-smoker (She is a non smoker). Concomitant products included LEVETIRACETAM and COLECALCIFEROL (VITAMIN D3 GUMMY) for an unknown indication.   On 01-Dec-2022, the patient received fourth dose of mRNA-1273 BIVALENT .222 (MODERNA COVID-19 VACCINE, BIVALENT (ORIGINAL AND OMICRON BA.4/BA.5)) (unknown route) 1 dosage form. On an unknown date, the patient started LEVOTHYROXINE (unknown route) once daily, FENOFIBRATE (unknown route) 48 milligram, PANTOPRAZOLE (unknown route) 40 milligram, OMEPRAZOLE (PROTONIX [OMEPRAZOLE]) (unknown route) 40 milligram, RIVAROXABAN (XARELTO) (unknown route) 200 milligram, ALLOPURINOL (unknown route) 500 milligram, FULVESTRANT (unknown route) 500 milligram, MAGNESIUM (MG [MAGNESIUM]) (unknown route) 2 milligram and LOPERAMIDE (unknown route) 2 mg 1-4x day as needed. On 18-Dec-2022, the patient experienced ENCEPHALITIS (Encephalitis) (seriousness criteria hospitalization and medically significant). On an unknown date, the patient experienced GAIT DISTURBANCE (She is agile but walks with the aid of a cane and a walker.She cannot currently drive). The patient was hospitalized from 19-Dec-2022 to 25-Dec-2022 due to ENCEPHALITIS. The patient was treated with PARACETAMOL (TYLENOL) for Headache, at an unspecified dose and frequency. At the time of the report, ENCEPHALITIS (Encephalitis) had not resolved and GAIT DISTURBANCE (She is agile but walks with the aid of a cane and a walker.She cannot currently drive) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Computerised tomogram: Inconclusive. On an unknown date, Electrocardiogram: Inconclusive. On an unknown date, Magnetic resonance imaging: Inconclusive.     For mRNA-1273 BIVALENT .222 (MODERNA COVID-19 VACCINE, BIVALENT (ORIGINAL AND OMICRON BA.4/BA.5)) (Unknown), the reporter did not provide any causality assessments.   It was reported as there were no symptoms had been reported to them from patients who had given the same lot number. Patient had first dose on 17 Feb 2021, second dose on 17 Mar 2021 (001B21A) and had first booster dose on 26 Nov 2021 (058H21A). It was reported as patient want to know as soon as possible as she is taking medication that can cause cardiac arrest. The patient had not receive any other vaccines in the 4 weeks prior to COVID-19 vaccine Patient husband wanted to bring her to the hospital at that time but she refused.  On 18 Dec 2022,she showed signs of delirium - she cannot say what her name was, the only thing she could answer was when her birthday was. She was taken to the hospital via an ambulance.  She spent 17 hours in the emergency room and 3 days in the ICU and was discharged on 25Dec2022.  While in the hospital several conditions were ruled out - stroke, brain cancer and tumor. The only thing that was shown was minimal swelling of the brain but her brain "looks good" so the diagnosis was encephalitis with delirium. She was given medication for seizure. They are trying to look for the connection to the cause of her condition.  She reports that she has been dealing with cancer for the past 17 years.  She states that she was a (name withheld) Law - where she does not show any signs of the condition.  Her insurance company refused to have her tested for ovarian cancer then as her markers were normal but after 4 years she eventually was diagnosed to had ovarian cancer, stage 4 and was given 4 months to live. That was in 2005.  She said that her cancer did not get worse after getting the Covid-19 vaccines.  She added that she also had neuropathy.  She was non drug user.  She states that she was doing very well considering and that she was on physical therapy. She states that she called their pharmacy and was told that no complaints came up from the batch of vaccines that were administered to her.  The symptoms of encephalitis included delirium and headache.  The symptom of gait disturbance included "she is agile but walks with the aid of a cane and a walker. She cannot currently drive".  Company comment: This spontaneous case concerns a 78-year-old female patient with no relevant medical history reported, who experienced the unexpected, serious (hospitalization and medically significant) event of encephalitis  17 days after the second booster dose of mRNA-1273.222. Initially, the patient experienced headache and delirium, for which she was admitted to the hospital for 6 days. She was evaluated with an ECG, MRI, and CT scan (results: inconclusive) where diagnosis such as stroke, brain cancer or other tumors were ruled out. The patient reports she was treated with seizure medication and later discharged. She was currently under physical therapy and walking with the aid of a cane and a walker. Information regarding clinical evaluation, diagnostic tests and treatment provided has not been disclosed. Outcome was reported as not resolved. The benefit-risk relationship of mRNA-1273 is not affected by this report.   This case was linked to MODERNATX, INC.-MOD-2023-705113 (E2B Linked Report).   Most recent FOLLOW-UP information incorporated above includes: On 26-Jan-2023: Live-significant follow up, event (headache, giat disturbance)  added , event outcome updated, patient information updated and concomitant drug information updated , narrative updated; Sender's Comments: This spontaneous case concerns a 78-year-old female patient with no relevant medical history reported, who experienced the unexpected, serious (hospitalization and medically significant) event of encephalitis 17 days after the second booster dose of mRNA-1273.222. Initially, the patient experienced headache and delirium, for which she was admitted to the hospital for 6 days. She was evaluated with an ECG, MRI, and CT scan (results: inconclusive) where diagnosis such as stroke, brain cancer or other tumors were ruled out. The patient reports she was treated with seizure medication and later discharged. She was currently under physical therapy and walking with the aid of a cane and a walker. Information regarding clinical evaluation, diagnostic tests and treatment provided has not been disclosed. Outcome was reported as not resolved. The benefit-risk relationship of mRNA-1273 is not affected by this report. MODERNATX, INC.-MOD-2023-705113:same reporter