More than 36 days after the first dose without receiving the second dose, received 2 dose on 30 march; had a powerful reaction; they felt like they had covid-19 again starting after 2 hours of getting the; really nauseated; had extreme fatigue; fever of 99°F-100°F; felt awful.; This spontaneous case was reported by an other health care professional and describes the occurrence of INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION (More than 36 days after the first dose without receiving the second dose, received 2 dose on 30 march), ADVERSE REACTION (had a powerful reaction), COVID-19 (they felt like they had covid-19 again starting after 2 hours of getting the), NAUSEA (really nauseated) and FATIGUE (had extreme fatigue) in a 73-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 021B21A and 026L20A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     The patient's past medical history included COVID-19 on 02-Jan-2021, Heart attack and Immune system disorder. Concurrent medical conditions included Disease risk factor and Immunocompromised.   On 30-Dec-2020, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 30-Mar-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 30-Mar-2021, the patient experienced ADVERSE REACTION (had a powerful reaction), COVID-19 (they felt like they had covid-19 again starting after 2 hours of getting the), NAUSEA (really nauseated), FATIGUE (had extreme fatigue), PYREXIA (fever of 99°F-100°F) and FEELING ABNORMAL (felt awful.). On an unknown date, the patient experienced INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION (More than 36 days after the first dose without receiving the second dose, received 2 dose on 30 march). On 30-Mar-2021, ADVERSE REACTION (had a powerful reaction), NAUSEA (really nauseated), FATIGUE (had extreme fatigue), PYREXIA (fever of 99°F-100°F) and FEELING ABNORMAL (felt awful.) outcome was unknown, COVID-19 (they felt like they had covid-19 again starting after 2 hours of getting the) had resolved. At the time of the report, INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION (More than 36 days after the first dose without receiving the second dose, received 2 dose on 30 march) had resolved.        For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter did not provide any causality assessments.   Treatment medications include monoclonal antibodies.  Caller was concerned that she received monoclonal antibodies and they could have interfered with his body's ability to properly produce antibodies.   This case was linked to MOD-2021-270554 (Patient Link).   Most recent FOLLOW-UP information incorporated above includes: On 29-Jul-2021: Upon follow up event onset date was amended On 29-Sep-2021: Significant Follow-up added- 2nd dose start date , events added as fatigue, nausea, fever and feeling abnormal; Sender's Comments: This is a  medication error case of inappropriate schedule of product administration (60 days between first and second doses) in a 73-year-old female patient with a relevant medical history of immunocompromised situation who experienced the unexpected non-serious events of Covid-19, feeling abnormal, nausea, fatigue and pyrexia. The events occurred on the same day after receiving second dose of Moderna mRNA-1273 vaccine. The rechallenge is not applicable as the details of first dose was not provided. The reporter did not provide the causality assessment. The medical history of immunocompromise and non-compliance to dosage schedule remains as confounders for the event Covid-19. The benefit-risk relationship of mRNA-1273 is not affected by this report.