Atrial fabrilation; pneumonitis; lung infection; Heart failure; This spontaneous case was reported by an other health care professional and describes the occurrence of PNEUMONITIS (pneumonitis), PNEUMONIA (lung infection), CARDIAC FAILURE (Heart failure) and ATRIAL FIBRILLATION (Atrial fabrilation) in a 71-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination.    Co-suspect product included non-company product CORIANDRUM SATIVUM, FOENICULUM VULGARE, GLYCYRRHIZA GLABRA, MATRICARIA RECUTITA, VERBENA OFFICINALIS (INFUSION DIGESTION) for Merkel cell carcinoma.    The patient's past medical history included Pneumonia on 27-Feb-2020. Concurrent medical conditions included Congestive heart failure since 1992.   On 13-Feb-2020, the patient started CORIANDRUM SATIVUM, FOENICULUM VULGARE, GLYCYRRHIZA GLABRA, MATRICARIA RECUTITA, VERBENA OFFICINALIS (INFUSION DIGESTION) (Intravenous) 500 mg every four weeks. On 23-Mar-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 25-Mar-2021, CORIANDRUM SATIVUM, FOENICULUM VULGARE, GLYCYRRHIZA GLABRA, MATRICARIA RECUTITA, VERBENA OFFICINALIS (INFUSION DIGESTION) (Intravenous) dosage was changed to 500 mg every four weeks. On 20-Apr-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 02-Jun-2021, CORIANDRUM SATIVUM, FOENICULUM VULGARE, GLYCYRRHIZA GLABRA, MATRICARIA RECUTITA, VERBENA OFFICINALIS (INFUSION DIGESTION) (Intravenous) dosage was changed to 500 mg every four weeks. On 14-Feb-2021, the patient experienced PNEUMONITIS (pneumonitis) (seriousness criterion hospitalization), PNEUMONIA (lung infection) (seriousness criteria hospitalization and medically significant) and CARDIAC FAILURE (Heart failure) (seriousness criteria hospitalization and medically significant). On 02-Apr-2021, the patient experienced ATRIAL FIBRILLATION (Atrial fabrilation) (seriousness criteria hospitalization and medically significant). The patient was hospitalized from 14-Feb-2021 to 18-Feb-2021 due to CARDIAC FAILURE, PNEUMONIA and PNEUMONITIS, and then from 02-Apr-2021 to 06-Apr-2021 due to ATRIAL FIBRILLATION. The patient was treated with LEVOFLOXACIN from 18-Feb-2021 to 24-Feb-2021 for Adverse event, at a dose of 1 dosage form; PREDNISONE (oral) from 18-Feb-2021 to 24-Mar-2021 for Adverse event, at a dose of 10 mg once a day; VANCOMYCIN from 15-Feb-2021 to 17-Feb-2021 for Adverse event, at an unspecified dose and frequency; CEFEPIME from 15-Feb-2021 to 17-Feb-2021 for Adverse event, at an unspecified dose and frequency; CEFTRIAXONE on 27-Mar-2021 for Adverse event, at a dose of 1 dosage form and AZITHROMYCIN 27-Mar-2021 for Adverse event, at an unspecified dose and frequency. On 18-Feb-2021, PNEUMONITIS (pneumonitis), PNEUMONIA (lung infection) and CARDIAC FAILURE (Heart failure) had resolved. On 06-Apr-2021, ATRIAL FIBRILLATION (Atrial fabrilation) had resolved. Not Provided    DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 11-Mar-2021, Scan: scans showed patchy areas in lungs (abnormal) scans showed patchy areas in lungs and INCMGA00012 was interrupted with the plan of treatment reevaluation in 2 weeks. On 02-Apr-2021, SARS-CoV-2 test: positive (Positive) Positive.     For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter did not provide any causality assessments.   Concomitant product use was not provided by the reporter. It was reported that the last dose of NCMGA00012 prior to the serious adverse events (SAEs) of lung infection: pneumonia (1st), pneumonitis(1st) and heart failure was administered on 11FEB2021. The last dose prior to the SAEs of lung infection: pneumonia (2nd), lung infection: pneumonia (3rd), atrial fibrillation C RVR, pneumonitis (2nd ) and administered on 25MAR2021.The action taken with INCMGA00012 due to the SAEs of pneumonitis (1st), lung infection: pneumonia (1st) and heart failure was reported as study treatment interrupted. On 26MAR2021 (study day 408), the subject experienced lung infection: pneumonia (2nd) and pneumonitis (2nd) and was admitted to an outside hospital. The action taken with INCMGA00012 due to the SAEs of pneumonitis (2nd) and lung infection: pneumonia (2nd) was continued unchanged. On 02APR2021 (study day 415), the subject was hospitalized with lung infection: pneumonia (3rd) and atrial fibrillation with rapid ventricular response (C RVR). The subject's wife reported that the subject tested positive for COVID-19 (not considered an SAE) upon arrival to the hospital. On 06APR2021, the outcome for the SAEs of atrial fibrillation C RVR and lung infection: pneumonia (3rd) was recovered/resolved and the subject was discharged. The action taken with INCMGA00012 due to the SAEs of pneumonia (3rd) and atrial fibrillation C RVR was reported as study treatment interrupted. On 02JUN2021, study treatment was discontinued per the physician's decision, as the subject was too weak to come back to the clinic. Based on the current available information and temporal association between the use of the product and the start date of the event, a causal relationship cannot be excluded. However, underlying medical history of pneumonia, congestive heart failure, be and oncological patient and use of concomitant medication are confounder.   This case was linked to MOD-2021-278384 (Patient Link).; Sender's Comments: Based on the current available information and temporal association between the use of the product and the start date of the event, a causal relationship cannot be excluded. However, underlying medical history of pneumonia, congestive heart failure, be and oncological patient and use of concomitant medication are confounder.