Covid rebound; Maternal exposure before pregnancy; This spontaneous prospective pregnancy case was reported by a nurse and describes the occurrence of COVID-19 (Covid rebound) and MATERNAL EXPOSURE BEFORE PREGNANCY (Maternal exposure before pregnancy) in a 34-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 051F21A, 046A21A and 029A21A) for COVID-19 vaccination.     The patient's past medical history included Allergic reaction. Concomitant products included MINERALS NOS, VITAMINS NOS (PRENATAL VITAMINS [MINERALS NOS;VITAMINS NOS]), VITAMIN D [VITAMIN D NOS] and DOXYLAMINE SUCCINATE, PYRIDOXINE HYDROCHLORIDE (BONJESTA) for an unknown indication.   On 27-Feb-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 28-Mar-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 19-Nov-2021, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. The patient's last menstrual period was on 15-Jan-2022 and the estimated date of delivery was 22-Oct-2022. On an unknown date, the patient experienced COVID-19 (Covid rebound) and MATERNAL EXPOSURE BEFORE PREGNANCY (Maternal exposure before pregnancy). The patient received mRNA-1273 (Moderna COVID-19 Vaccine) during pregnancy.  At the time of the report, COVID-19 (Covid rebound) was resolving and MATERNAL EXPOSURE BEFORE PREGNANCY (Maternal exposure before pregnancy) had resolved.        For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter did not provide any causality assessments.   The patient was taking other medications within 2 weeks of starting COVID-19 treatment. Other medication from Pfizer by oral route was received by the patient from 11-May-2022 to 16-May-2022 for COVID-19 treatment. Device Date was reported as 26-May-2022. Company comment: This spontaneous case concerns a 34-year-old, female patient with no relevant medical history, who experienced the unexpected, non-serious AESI of COVID-19. Maternal exposure before pregnancy was also reported. The exact date onset of the event COVID-19 was not specified in respect to the administration of a dose of mRNA-1273, hence latency could not be assessed. The third dose of mRNA-1273 was given 8 months after the initial two doses, the interval between the two doses of mRNA-1273 is 29 days. Details of concomitant medications, medical history, clinical course and treatment were not provided. The benefit-risk relationship of mRNA-1273 is not affected by this report.; Sender's Comments: This spontaneous case concerns a 34-year-old, female patient with no relevant medical history, who experienced the unexpected, non-serious AESI of COVID-19. Maternal exposure before pregnancy was also reported. The exact date onset of the event COVID-19 was not specified in respect to the administration of a dose of mRNA-1273, hence latency could not be assessed. The third dose of mRNA-1273 was given 8 months after the initial two doses, the interval between the two doses of mRNA-1273 is 29 days. Details of concomitant medications, medical history, clinical course and treatment were not provided. The benefit-risk relationship of mRNA-1273 is not affected by this report.