Tongue was numb/numbness of the tip of my tongue and mouth; Runny nose; Feels like cardiac arhythmia; Discomfort on her chest; Fever; Swelling of the arm of the injection; Her face was red; Muscle tightness; Bitter taste; Chills; Fatigue; Headache; This spontaneous case was reported by an other health care professional and describes the occurrence of ARRHYTHMIA (Feels like cardiac arhythmia) in a 58-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 010M20A and 036L30A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Concurrent medical conditions included Drug allergy. Concomitant products included ESTROGENS ESTERIFIED, METHYLTESTOSTERONE (ESTRATEST) from 01-Nov-2020 to an unknown date, PRASTERONE (INTRAROSA) and ESTRADIOL for Hormone therapy, TEMAZEPAM for Sleep disorder therapy, CLONAZEPAM for an unknown indication.   On 08-Jan-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 05-Feb-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On 05-Feb-2021, the patient experienced CHEST DISCOMFORT (Discomfort on her chest), ERYTHEMA (Her face was red), PYREXIA (Fever) and VACCINATION SITE SWELLING (Swelling of the arm of the injection). On an unknown date, the patient experienced ARRHYTHMIA (Feels like cardiac arhythmia) (seriousness criterion medically significant), HYPOAESTHESIA (Tongue was numb/numbness of the tip of my tongue and mouth), MUSCLE TIGHTNESS (Muscle tightness), DYSGEUSIA (Bitter taste), RHINORRHOEA (Runny nose), CHILLS (Chills), FATIGUE (Fatigue) and HEADACHE (Headache). At the time of the report, ARRHYTHMIA (Feels like cardiac arhythmia) and HYPOAESTHESIA (Tongue was numb/numbness of the tip of my tongue and mouth) had not resolved and CHEST DISCOMFORT (Discomfort on her chest), ERYTHEMA (Her face was red), MUSCLE TIGHTNESS (Muscle tightness), DYSGEUSIA (Bitter taste), RHINORRHOEA (Runny nose), CHILLS (Chills), FATIGUE (Fatigue), HEADACHE (Headache), PYREXIA (Fever) and VACCINATION SITE SWELLING (Swelling of the arm of the injection) had resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 23-Jan-2021, SARS-CoV-2 test: positive (Positive) Positive.     For mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular), the reporter considered ARRHYTHMIA (Feels like cardiac arhythmia), CHEST DISCOMFORT (Discomfort on her chest), HYPOAESTHESIA (Tongue was numb/numbness of the tip of my tongue and mouth), ERYTHEMA (Her face was red), MUSCLE TIGHTNESS (Muscle tightness), DYSGEUSIA (Bitter taste), RHINORRHOEA (Runny nose), CHILLS (Chills), FATIGUE (Fatigue), HEADACHE (Headache), PYREXIA (Fever) and VACCINATION SITE SWELLING (Swelling of the arm of the injection) to be possibly related.    No treatment information was provided.  Based on the current available information and temporal association between the use of the product and the start dates of the events, a causal relationship cannot be excluded   This case was linked to US-MODERNATX, INC.-MOD-2021-049938 (Patient Link).   Most recent FOLLOW-UP information incorporated above includes: On 28-Apr-2021: Case upgraded to serious, updated patient medical history, laboratory data, suspect product details, concomitant medications, event details and reporter causality.; Sender's Comments: Based on the current available information and temporal association between the use of the product and the start dates of the events, a causal relationship cannot be excluded.