second dose made it worse; increased seizure activity; some memory loss; motor control issue; out of work/ Have been unable to work since April 17th, 2021; loss of coordination in legs while walking/ loss of leg movement coordination; body aches; fevers ranging between 100-100.2 and a half for 10-20 hours a day/fevers ranging different temperatures on different parts of his head; extreme fatigue; headache/ severe headache; joint aches; This spontaneous case was reported by a consumer and describes the occurrence of SEIZURE (increased seizure activity) in a 56-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 042B21-2A and 006B21A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Concurrent medical conditions included Drug allergy (Codeine allergy), Penicillin allergy, Drug allergy (Azithromycin allergy), Drug allergy (Dilantin allergy), Drug allergy (Trazadone allergy), Drug allergy (Levaquin allergy), Drug allergy (Aspirin allergy), Food allergy (Yellow onions allergy), Seafood allergy (All seafood except shrimp and flounder), Food allergy (Mild dairy allergy), Allergy to vaccine (Tetanus shot allergy), Allergy to vaccine (Flu shot allergy), Arthritis (worsening ever since received 1st vaccine.) since 01-Jun-1977, Asthma since 01-Feb-1987, Seizure (Frequency has increased by 300% since 2nd vaccine) since 01-Jul-1988, Aortic aneurysm (Aortic muscle damage caused by aneurysm) since 10-Oct-2011 and Crohn's disease since 01-May-1989. Concomitant products included BECLOMETASONE DIPROPIONATE (QVAR REDIHALER) from 01-Aug-1998 to an unknown date for Asthma, MIRTAZAPINE from 01-Feb-2014 to an unknown date for Sleep disorder, MELATONIN, CALCIUM, MAGNESIUM, POTASSIUM, DIPHENHYDRAMINE HYDROCHLORIDE (BENADRYL [DIPHENHYDRAMINE HYDROCHLORIDE]), ZINC, INOSITOL and IODINE (KELP [IODINE]) for an unknown indication.   On 20-Mar-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 17-Apr-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On 17-Apr-2021, the patient experienced IMPAIRED WORK ABILITY (out of work/ Have been unable to work since April 17th, 2021), PYREXIA (fevers ranging between 100-100.2 and a half for 10-20 hours a day/fevers ranging different temperatures on different parts of his head), FATIGUE (extreme fatigue) and HEADACHE (headache/ severe headache). 17-Apr-2021, the patient experienced COORDINATION ABNORMAL (loss of coordination in legs while walking/ loss of leg movement coordination), MYALGIA (body aches) and ARTHRALGIA (joint aches). On 17-Apr-2021 at 11:00 PM, the patient experienced AMNESIA (some memory loss) and MOTOR DYSFUNCTION (motor control issue). On 20-Apr-2021, the patient experienced SEIZURE (increased seizure activity) (seriousness criterion medically significant). On 20-Apr-2021 at 1:00 PM, the patient experienced CONDITION AGGRAVATED (second dose made it worse). The patient was treated with NAPROXEN SODIUM (ALEVE) for Adverse event, at a dose of UNK dosage form. At the time of the report, SEIZURE (increased seizure activity), CONDITION AGGRAVATED (second dose made it worse), AMNESIA (some memory loss), MOTOR DYSFUNCTION (motor control issue), IMPAIRED WORK ABILITY (out of work/ Have been unable to work since April 17th, 2021), COORDINATION ABNORMAL (loss of coordination in legs while walking/ loss of leg movement coordination), MYALGIA (body aches), PYREXIA (fevers ranging between 100-100.2 and a half for 10-20 hours a day/fevers ranging different temperatures on different parts of his head), FATIGUE (extreme fatigue), HEADACHE (headache/ severe headache) and ARTHRALGIA (joint aches) had not resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 07-May-2021, Antinuclear antibody: negative (Negative) negative. On 07-May-2021, Blood thyroid stimulating hormone (0.35-5.50): 3.19 (normal) 3.19 uIU/mL. On 07-May-2021, C-reactive protein: 0.5 (Low) <0.5 mg/dL. On 07-May-2021, Electrophoresis: normal (normal) No monoclonal proteins seen on serum. On 07-May-2021, Full blood count: normal (normal) Normal values. On 07-May-2021, Metabolic function test: normal (normal) Normal values. On 07-May-2021, Red blood cell sedimentation rate (0-15): 3 (normal) 3 mm/h. On 07-May-2021, Urine analysis: normal (normal) Normal values. On 07-May-2021, White blood cell count (4.0-10.5): 5.9 (normal) 5.9 K/uL. On 14-May-2021, Computerised tomogram: normal (normal) Normal study. On 17-May-2021, Computerised tomogram: normal (normal) Normal study. On 01-Jun-2021, Blood culture: no growth (normal) no growth.         Lab investigations done 0n 05-May2021,included Quantiferon TB gold plus test which was reported as negative and Lyme antibodies, IgG and IgM tests which were reported as negative. Concomitant medications included various vitamins, minerals, enzymes,herbal extracts, amino acids and diet supplements. Patient reported that his primary care physician ordered a battery of lab investigations to rule out other causes than the vaccine for his symptoms, but the results were negative. The patient also maintained a log of the temperature fluctuations since 13-May-2021, for his doctor to establish a pattern. He reported that he has not been able to walk more than half a mile without getting extremely fatigued. He was not able to go to work since 17 April 2021.  Based on the current available information and temporal association between the use of the product and the start date of the events, a causal relationship cannot be excluded.   This case was linked to MOD-2021-109846 (Patient Link).   Most recent FOLLOW-UP information incorporated above includes: On 06-May-2021: No specific follow-up information recorded. On 06-May-2021: Added non significant information which was patient's address and contact details. On 02-Jun-2021: No new information. On 07-Jun-2021: Added patient demographics, medical history, concomitant medications, lab test data,  new events and case was upgraded to serious due to Seizure event.; Sender's Comments: Based on the current available information and temporal association between the use of the product and the start date of the events, a causal relationship cannot be excluded.