Expired doses administered; 0.25ml administered as second dose; Maternal exposure during pregnancy; Dose 1 on 7-Apr-2021 and Dose 2 on 7-Apr-2022; This spontaneous prospective pregnancy case was reported by an other health care professional and describes the occurrence of EXPIRED PRODUCT ADMINISTERED (Expired doses administered), UNDERDOSE (0.25ml administered as second dose), INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION (Dose 1 on 7-Apr-2021 and Dose 2 on 7-Apr-2022) and MATERNAL EXPOSURE DURING PREGNANCY (Maternal exposure during pregnancy) in a 34-year-old female patient who received mRNA-1273 (Spikevax) (batch no. 069H21A) for COVID-19 vaccination.     Patient had no known allergies. It was reported, chronic or long standing health condition and acute illness at the time or before vaccination were unknown. Also, it was unknown if patient had ever been diagnosed with or tested positive for COVID-19.    On 07-Apr-2021, the patient received first dose of mRNA-1273 (Spikevax) (unknown route) 1 dosage form. On 07-Apr-2022, received second dose of mRNA-1273 (Spikevax) (Intramuscular) dosage was changed to .25 milliliter. Last menstrual period and estimated date of delivery were not provided. On 07-Apr-2021, the patient experienced INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION (Dose 1 on 7-Apr-2021 and Dose 2 on 7-Apr-2022). On 07-Apr-2022, the patient experienced EXPIRED PRODUCT ADMINISTERED (Expired doses administered), UNDERDOSE (0.25ml administered as second dose) and MATERNAL EXPOSURE DURING PREGNANCY (Maternal exposure during pregnancy). On 07-Apr-2022, MATERNAL EXPOSURE DURING PREGNANCY (Maternal exposure during pregnancy) had resolved. At the time of the report, EXPIRED PRODUCT ADMINISTERED (Expired doses administered), UNDERDOSE (0.25ml administered as second dose) and INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION (Dose 1 on 7-Apr-2021 and Dose 2 on 7-Apr-2022) outcome was unknown.        For mRNA-1273 (Spikevax) (Unknown), the reporter did not provide any causality assessments.   No concomitant and treatment medications were reported. Vaccine received had an expiration date of 26-Apr-2022, as it came with sticker of that. However, the manufacturer expiration date was 06-Apr-2022. They were taken out of the freezer on 05-Apr-2022. The patient had no adverse reaction to the vaccine after administration. It was reported, batch/Lot number and Expiration date was 066K21A for unknown dose  Company comment: This spontaneous case concerns a 34 year old female patient with reported Maternal exposure during pregnancy on receiving the second dose of mRNA-1273 vaccine. Patient received the second dose about 1 year after the first dose which is suggestive of Inappropriate schedule of product administration. It was reported that the second dose was an underdose (0.25ml) and was expired as per the manufacturer's expiration date. No adverse events were reported. The benefit-risk relationship of mRNA-1273 is not affected by this report.   This case was linked to MOD-2022-538516, MOD-2022-538543, MOD-2022-538544 (Patient Link).   Most recent FOLLOW-UP information incorporated above includes: On 11-Apr-2022: Significant follow-up received on 11-Apr-2022 includes updated patient identifier, pregnancy information, dose regimen and events.; Sender's Comments: This spontaneous case concerns a 34 year old female patient with reported Maternal exposure during pregnancy on receiving the second dose of mRNA-1273 vaccine. Patient received the second dose about 1 year after the first dose which is suggestive of Inappropriate schedule of product administration. It was reported that the second dose was an underdose (0.25ml) and was expired as per the manufacturer's expiration date. No adverse events were reported. The benefit-risk relationship of mRNA-1273 is not affected by this report.