Feeling a bit flushed; Heart was beating very hard and very fast; All a sudden she had severe back muscle pain that started hurting/Muscle pain eventually moved to the front of her body/Pain moved to the skin on her throat as well; Little soreness on her arm; Tightness in her chest which started near her throat and eventually went down further to her chest; Feeling as to when she had an allergic reaction to the amoxicillin; Felt tired; This spontaneous case was reported by a consumer and describes the occurrence of CHEST DISCOMFORT (Tightness in her chest which started near her throat and eventually went down further to her chest), PAIN IN EXTREMITY (Little soreness on her arm), FLUSHING (Feeling a bit flushed), HEART RATE INCREASED (Heart was beating very hard and very fast) and ADVERSE EVENT (Feeling as to when she had an allergic reaction to the amoxicillin) in a 45-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 047A21A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Concurrent medical conditions included Drug allergy (Allergic reaction to the amoxicillin.). Concomitant products included CENTRUM WOMEN, VITAMIN B-COMPLEX VITAMIN C, ISOSORBIDE MONONITRATE (FLO), BENZONATATE, AMOXICILLIN TRIHYDRATE, CLARITHROMYCIN, ESOMEPRAZOLE MAGNESIUM (NEXIUM 1-2-3) and SALBUTAMOL (ALBUTEROL HFA) for an unknown indication.    On 21-Mar-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 21-Mar-2021, the patient experienced CHEST DISCOMFORT (Tightness in her chest which started near her throat and eventually went down further to her chest), ADVERSE EVENT (Feeling as to when she had an allergic reaction to the amoxicillin) and FATIGUE (Felt tired). On 22-Mar-2021, the patient experienced PAIN IN EXTREMITY (Little soreness on her arm). On 24-Mar-2021, the patient experienced FLUSHING (Feeling a bit flushed), HEART RATE INCREASED (Heart was beating very hard and very fast) and MYALGIA (All a sudden she had severe back muscle pain that started hurting/Muscle pain eventually moved to the front of her body/Pain moved to the skin on her throat as well). The patient was treated with DIPHENHYDRAMINE HYDROCHLORIDE (BENADRYL [DIPHENHYDRAMINE HYDROCHLORIDE]) at an unspecified dose and frequency. On 21-Mar-2021, CHEST DISCOMFORT (Tightness in her chest which started near her throat and eventually went down further to her chest), ADVERSE EVENT (Feeling as to when she had an allergic reaction to the amoxicillin) and FATIGUE (Felt tired) had resolved. On 22-Mar-2021, PAIN IN EXTREMITY (Little soreness on her arm) had resolved. At the time of the report, FLUSHING (Feeling a bit flushed) and HEART RATE INCREASED (Heart was beating very hard and very fast) had resolved and MYALGIA (All a sudden she had severe back muscle pain that started hurting/Muscle pain eventually moved to the front of her body/Pain moved to the skin on her throat as well) outcome was unknown.        The action taken with mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) was unknown.   For mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular), the reporter did not provide any causality assessments.