conjunctive heart failure; slept all the time; wound up very very sick; many side effects, next day I had a lot of side effects; lost 40 pounds; didn't eat food for 6 weeks; upset, next day I was not myself anymore; She didn't want to get the second dose; This spontaneous case was reported by a consumer and describes the occurrence of CARDIAC FAILURE CONGESTIVE (conjunctive heart failure) in a female patient of an unknown age who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     No Medical History information was reported.    On 27-Jul-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 27-Jul-2021, the patient experienced INTENTIONAL DOSE OMISSION (She didn't want to get the second dose). On an unknown date, the patient experienced CARDIAC FAILURE CONGESTIVE (conjunctive heart failure) (seriousness criteria hospitalization and medically significant), HYPERSOMNIA (slept all the time), ILLNESS (wound up very very sick), VACCINATION COMPLICATION (many side effects, next day I had a lot of side effects), ABNORMAL LOSS OF WEIGHT (lost 40 pounds), DECREASED APPETITE (didn't eat food for 6 weeks) and FEELING ABNORMAL (upset, next day I was not myself anymore). The patient was hospitalized for 6 days due to CARDIAC FAILURE CONGESTIVE. On 27-Jul-2021, INTENTIONAL DOSE OMISSION (She didn't want to get the second dose) had resolved. At the time of the report, CARDIAC FAILURE CONGESTIVE (conjunctive heart failure) had not resolved and HYPERSOMNIA (slept all the time), ILLNESS (wound up very very sick), VACCINATION COMPLICATION (many side effects, next day I had a lot of side effects), ABNORMAL LOSS OF WEIGHT (lost 40 pounds), DECREASED APPETITE (didn't eat food for 6 weeks) and FEELING ABNORMAL (upset, next day I was not myself anymore) outcome was unknown.        The action taken with mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) was unknown.       Symptoms: It was reported that the patient did not wanted second dose of vaccine because she was affected by first one, She was undergone many tests, she had many side effects, she was healthy and her immune system was good, her doctor did not warned her with ingredients and possible side effects of vaccine. She felt like she was being poisoned, and was continued treatment for heart condition.  No concomitant medications were reported No treatment medications were reported  Company comment: This is a spontaneous case concerning a female patient of unknown age, with no reported medical history, who experienced the serious (due to hospitalization and medically important condition) unexpected, AESI of Cardiac failure congestive. The event occurred on an unknown date after the first dose of mRNA-1273 vaccine. The outcome of the event was reported as not recovered. The patient was hospitalized for 6 days. Additionally, Intentional dose omission was reported in this case. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.   Reporter did not allow further contact; Sender's Comments: This is a spontaneous case concerning a female patient of unknown age, with no reported medical history, who experienced the serious (due to hospitalization and medically important condition) unexpected, AESI of Cardiac failure congestive. The event occurred on an unknown date after the first dose of mRNA-1273 vaccine. The outcome of the event was reported as not recovered. The patient was hospitalized for 6 days. Additionally, Intentional dose omission was reported in this case. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.