Weak; Bedridden; Lost of weigh; Encephalitis of herpes / trouble with concentrate , memory issues , like memory lost; Anti nmda receptor encephalitis; This spontaneous case was reported by a patient family member or friend and describes the occurrence of ASTHENIA (Weak), BEDRIDDEN (Bedridden), MENINGOENCEPHALITIS HERPETIC (Encephalitis of herpes / trouble with concentrate , memory issues , like memory lost) and ENCEPHALITIS AUTOIMMUNE (Anti nmda receptor encephalitis) in a 50-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 041J21A) for COVID-19 prophylaxis. The occurrence of additional non-serious events is detailed below.     The patient's past medical history included COVID-19 on 21-Mar-2021.    On 12-Jan-2022, the patient received dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 08-Sep-2022, the patient experienced ASTHENIA (Weak) (seriousness criterion hospitalization), BEDRIDDEN (Bedridden) (seriousness criterion hospitalization), MENINGOENCEPHALITIS HERPETIC (Encephalitis of herpes / trouble with concentrate , memory issues , like memory lost) (seriousness criterion medically significant) and ENCEPHALITIS AUTOIMMUNE (Anti nmda receptor encephalitis) (seriousness criterion medically significant). On an unknown date, the patient experienced WEIGHT DECREASED (Lost of weigh). At the time of the report, ASTHENIA (Weak), BEDRIDDEN (Bedridden), MENINGOENCEPHALITIS HERPETIC (Encephalitis of herpes / trouble with concentrate , memory issues , like memory lost), ENCEPHALITIS AUTOIMMUNE (Anti nmda receptor encephalitis) and WEIGHT DECREASED (Lost of weigh) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Blood test: normal.. On an unknown date, Electrogastrogram: normal.. On an unknown date, Magnetic resonance imaging: normal..     For mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular), the reporter did not provide any causality assessments.   No concomitant medication information was reported.       The reporter stated that two weeks later, after my husband took the vaccine (Booster), I and the kids started to notice something different like- trouble with concentrate, memory issues like memory lost. After since the patient was getting worsen. We went to a Neurologist and prescribed a lot of test and exams and all those came normal. Month after the patient getting worsen them ever, no follow commander, lost of weigh. So the patient end up three different hospital, with a lot of test, with no diagnosis. After 3 months spent in the hospital, the patient was weak and bedridden all the time, no following any command , with a tube feeding.  No treatment medication information was reported.  It was unknown if the patient experienced any additional symptoms/events. The patient had no medical history, concomitant disease or risk factor. There were no lab data/results available.  Company Comment :This spontaneous case concerns a 50-year-old male patient with no medical history, concomitant disease or risk factor, who experienced the unexpected and serious (medically significant) events of meningoencephalitis herpetic and encephalitis autoimmune along with the unexpected serious (hospitalization) events of asthenia and bedridden approximately 7 months after a booster dose of mRNA-1273 vaccine, was administered. It was reported that two weeks after patient received the vaccine patient had trouble with concentration, memory issues, like memory lost. After since his was getting worse. He went to a neurologist and was prescribed a lot of test and exams (blood work, MRI and ECG) all those came normal. Month after he was getting worse, no follow commander, loss of weigh. After 3 months spent in hospital, he was a weak person, bedridden all the time, no following any command, with a tube feeding. So far, the diagnosis he's having right now it's: encephalitis of herpes and anti-NMDA-receptor encephalitis. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.; Sender's Comments: This spontaneous case concerns a 50-year-old male patient with no medical history, concomitant disease or risk factor, who experienced the unexpected and serious (medically significant) events of meningoencephalitis herpetic and encephalitis autoimmune along with the unexpected serious (hospitalization) events of asthenia and bedridden approximately 7 months after a booster dose of mRNA-1273 vaccine, was administered. It was reported that two weeks after patient received the vaccine patient had trouble with concentration, memory issues, like memory lost. After since his was getting worse. He went to a neurologist and was prescribed a lot of test and exams (blood work, MRI and ECG) all those came normal. Month after he was getting worse, no follow commander, loss of weigh. After 3 months spent in hospital, he was a weak person, bedridden all the time, no following any command, with a tube feeding. So far, the diagnosis he's having right now it's: encephalitis of herpes and anti-NMDA-receptor encephalitis. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.