hard to think, it has been very disturbing because he has to think for work, and it has been very difficult; Continued bad and strange dizziness; vertigo that lasted about 3 weeks and was very disturbing; heart was pounding but heart rate was normal; couldn't sleep; brain fogs; hard to think and remember things; feeling of anxiety; There were times when he feels detached from reality; strange feeling of dizziness and nausea feeling; At some point felt like he was almost going to lose consciousness; felling sick like he had the flu; significant pain in arm; fever; chills; This spontaneous case was reported by a consumer (subsequently medically confirmed) and describes the occurrence of MENTAL IMPAIRMENT (hard to think, it has been very disturbing because he has to think for work, and it has been very difficult), DIZZINESS (Continued bad and strange dizziness), VERTIGO (vertigo that lasted about 3 weeks and was very disturbing), PALPITATIONS (heart was pounding but heart rate was normal), INSOMNIA (couldn't sleep), FEELING ABNORMAL (brain fogs), MEMORY IMPAIRMENT (hard to think and remember things), ANXIETY (feeling of anxiety), DISSOCIATION (There were times when he feels detached from reality) and NAUSEA (strange feeling of dizziness and nausea feeling) in a 55-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 044A21A and 011A21A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Concurrent medical conditions included Allergy (Respiratory allergies).   On 01-Mar-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 29-Mar-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On 29-Mar-2021, the patient experienced INFLUENZA LIKE ILLNESS (felling sick like he had the flu), PAIN IN EXTREMITY (significant pain in arm), PYREXIA (fever) and CHILLS (chills). In April 2021,  after starting mRNA-1273 (Moderna COVID-19 Vaccine), the patient experienced MENTAL IMPAIRMENT (hard to think, it has been very disturbing because he has to think for work, and it has been very difficult) (seriousness criterion medically significant), DIZZINESS (Continued bad and strange dizziness) (seriousness criterion medically significant), VERTIGO (vertigo that lasted about 3 weeks and was very disturbing) (seriousness criterion medically significant), PALPITATIONS (heart was pounding but heart rate was normal) (seriousness criterion medically significant), INSOMNIA (couldn't sleep) (seriousness criterion medically significant), FEELING ABNORMAL (brain fogs) (seriousness criterion medically significant), MEMORY IMPAIRMENT (hard to think and remember things) (seriousness criterion medically significant), ANXIETY (feeling of anxiety) (seriousness criterion medically significant), DISSOCIATION (There were times when he feels detached from reality) (seriousness criterion medically significant), NAUSEA (strange feeling of dizziness and nausea feeling) (seriousness criterion medically significant) and PRESYNCOPE (At some point felt like he was almost going to lose consciousness). At the time of the report, MENTAL IMPAIRMENT (hard to think, it has been very disturbing because he has to think for work, and it has been very difficult), PALPITATIONS (heart was pounding but heart rate was normal), INSOMNIA (couldn't sleep), FEELING ABNORMAL (brain fogs), MEMORY IMPAIRMENT (hard to think and remember things), ANXIETY (feeling of anxiety), DISSOCIATION (There were times when he feels detached from reality), NAUSEA (strange feeling of dizziness and nausea feeling), PRESYNCOPE (At some point felt like he was almost going to lose consciousness), INFLUENZA LIKE ILLNESS (felling sick like he had the flu), PAIN IN EXTREMITY (significant pain in arm), PYREXIA (fever) and CHILLS (chills) outcome was unknown, DIZZINESS (Continued bad and strange dizziness) had not resolved and VERTIGO (vertigo that lasted about 3 weeks and was very disturbing) had resolved.            Patient reports he takes supplements as concomitant medications Patient was prescribed clonazepam for his anxiety and took ibuprofen for his symptoms. Patient went to the ER two weeks after receiving the second dose of the vaccine, he was checked out, ran some tests and everything was within normal limits. Blood work was normal.  The patient received both scheduled doses of mRNA-1273 prior to the events therefore, action taken with the drug in response to the events was not applicable.  Company comment: Based on the information provided which includes a strong temporal association between the use of mRNA-1273 vaccine and onset of the reported events, a causal relationship cannot be excluded. Chills and pyrexia are consistent with the product safety profile.   This case was linked to MOD-2021-090675 (Patient Link).; Sender's Comments: Based on the information provided which includes a strong temporal association between the use of mRNA-1273 vaccine and onset of the reported events, a causal relationship cannot be excluded. Chills and pyrexia are consistent with the product safety profile