Invalid Bivalent dose adminstered; No adverse event; Maternal exposure during pregnancy; This spontaneous prospective pregnancy case was reported by a nurse and describes the occurrence of UNDERDOSE (Invalid Bivalent dose adminstered), MATERNAL EXPOSURE DURING PREGNANCY (Maternal exposure during pregnancy) and NO ADVERSE EVENT (No adverse event) in a 44-year-old female patient who received mRNA-1273 BIVALENT .222 (MODERNA COVID-19 VACCINE, BIVALENT (ORIGINAL AND OMICRON BA.4/BA.5)) (batch no. AS7147B) for COVID-19 prophylaxis.     Concurrent medical conditions included Blood pressure high and Diabetes.    On 15-Sep-2022, the patient received dose of mRNA-1273 BIVALENT .222 (MODERNA COVID-19 VACCINE, BIVALENT (ORIGINAL AND OMICRON BA.4/BA.5)) (Intramuscular) .25 milliliter. Last menstrual period and estimated date of delivery were not provided. On 15-Sep-2022, the patient experienced MATERNAL EXPOSURE DURING PREGNANCY (Maternal exposure during pregnancy). On an unknown date, the patient experienced UNDERDOSE (Invalid Bivalent dose adminstered) and NO ADVERSE EVENT (No adverse event). On 15-Sep-2022, MATERNAL EXPOSURE DURING PREGNANCY (Maternal exposure during pregnancy) had resolved. At the time of the report, UNDERDOSE (Invalid Bivalent dose adminstered) and NO ADVERSE EVENT (No adverse event) outcome was unknown. Not Provided      For mRNA-1273 BIVALENT .222 (MODERNA COVID-19 VACCINE, BIVALENT (ORIGINAL AND OMICRON BA.4/BA.5)) (Intramuscular), the reporter considered UNDERDOSE (Invalid Bivalent dose adminstered) and NO ADVERSE EVENT (No adverse event) to be not related. No further causality assessment was provided for MATERNAL EXPOSURE DURING PREGNANCY (Maternal exposure during pregnancy).    No concomitant and treatment medications were reported. Patient had never been diagnosed with/ tested positive for COVID-19. It was unknown if the patient had acute illness at the time of vaccination and upto one month before. It was unknown if prescriptions. over the counter medications, dietary supplements, or herbal remedies being taken at time of vaccination and/or at the time of the adverse event. The event did not cause the patient to seek medical care. There were no other potential causes.  It was unknown if the patient had experienced a similar event in the past. It was reported that the patient made aware received a  0.25 mL of Moderna Bivalent Booster dose. Patient verbalized understanding. Patient denies having distress at this time. Patient denied having to go to the Emergency room or Primary Care provider. Informed the patient according to Moderna the recommendation was to re vaccinate with full dose in 8 weeks from 9/15/2022. Patient stated would like to be re vaccinated. Patient made aware will reach out to patient regarding receiving full vaccination.  Company Comment: This Regulatory Authority prospective pregnancy case was reported by a nurse and concerns a 44-year-old female patient, with no relevant medical history, who describes the occurrence of Underdose. Patient received 0.25ml of mRNA-1273.222 vaccine, administered as a booster dose within COVID-19 vaccination schedule. Last menstrual period and estimated date of delivery were not provided. The benefit-risk relationship of mRNA-1273.222 vaccine is not affected by this report.; Sender's Comments: This Regulatory Authority prospective pregnancy case was reported by a nurse and concerns a 44-year-old female patient, with no relevant medical history, who describes the occurrence of Underdose. Patient received 0.25ml of mRNA-1273.222 vaccine, administered as a booster dose within COVID-19 vaccination schedule. Last menstrual period and estimated date of delivery were not provided. The benefit-risk relationship of mRNA-1273.222 vaccine is not affected by this report.