Fainting after she received the booster; sick to stomach after she received the booster; felt weak and not herself after she received the booster; felt weak and not herself after she received the booster; blurred vision; pulse went up to 104 bpm after she received the booster; dizzy; Felt achy all over after she received the booster; a terrible headache after she received the booster; swelling under left arm lymph nodes/swelling under arm after she received the booster; left arm hurt after she received the booster; This spontaneous case was reported by a consumer and describes the occurrence of SYNCOPE (Fainting after she received the booster) in a 76-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Concurrent medical conditions included Atrial fibrillation. Concomitant products included METOPROLOL, LEVOTHYROXINE SODIUM (SYNTHROID) and VALSARTAN (DIOVAN) for an unknown indication.   On 19-Apr-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On an unknown date, the patient received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On an unknown date, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 06-Dec-2021, the patient experienced SYNCOPE (Fainting after she received the booster) (seriousness criterion medically significant), ABDOMINAL DISCOMFORT (sick to stomach after she received the booster), ASTHENIA (felt weak and not herself after she received the booster), FEELING ABNORMAL (felt weak and not herself after she received the booster), VISION BLURRED (blurred vision), HEART RATE INCREASED (pulse went up to 104 bpm after she received the booster), DIZZINESS (dizzy), MYALGIA (Felt achy all over after she received the booster), HEADACHE (a terrible headache after she received the booster), LYMPHADENOPATHY (swelling under left arm lymph nodes/swelling under arm after she received the booster) and VACCINATION SITE PAIN (left arm hurt after she received the booster). At the time of the report, SYNCOPE (Fainting after she received the booster), ABDOMINAL DISCOMFORT (sick to stomach after she received the booster), ASTHENIA (felt weak and not herself after she received the booster), FEELING ABNORMAL (felt weak and not herself after she received the booster), VISION BLURRED (blurred vision), HEART RATE INCREASED (pulse went up to 104 bpm after she received the booster), DIZZINESS (dizzy), MYALGIA (Felt achy all over after she received the booster) and VACCINATION SITE PAIN (left arm hurt after she received the booster) outcome was unknown and HEADACHE (a terrible headache after she received the booster) and LYMPHADENOPATHY (swelling under left arm lymph nodes/swelling under arm after she received the booster) had not resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 06-Dec-2021, Heart rate: 104 (High) pulse went up to 104 bpm after receiving booster.         No history of myocarditis or pericarditis. No treatment information was provided.   This case was linked to MOD-2021-406388 (Link).; Sender's Comments: This case concerns a 76-year-old, female patient with relevant medical history of atrial fibrillation, who experienced the unexpected event of Syncope. The event occurred approximately 7month 18 days after the booster dose of mRNA (Moderna covid-19 vaccine). The rechallenge was not applicable as event occurred after booster dose. However, this patient underlying medical condition remains a contributory factor. The benefit-risk relationship of mRNA-1273 (Moderna covid-19 vaccine) is not affected by this report.