Vial was expired on 13-May-2022, stored in refrigerator on 21-Jan-2022 and administered on 07-Jun-2022; No adverse event; Vaccine was administered on 7 June 2022 after the expiration date of 13 May 2022.; patient received 0.25 ml as dose 1; This spontaneous case was reported by a nurse and describes the occurrence of EXPIRED PRODUCT ADMINISTERED (Vaccine was administered on 7 June 2022 after the expiration date of 13 May 2022.), PRODUCT STORAGE ERROR (Vial was expired on 13-May-2022, stored in refrigerator on 21-Jan-2022 and administered on 07-Jun-2022), UNDERDOSE (patient received 0.25 ml as dose 1) and NO ADVERSE EVENT (No adverse event) in a 20-year-old female patient who received mRNA-1273 (Spikevax) (batch no. 003K21-2A) for COVID-19 prophylaxis. The patient was never diagnosed with/ tested positive for COVID-19. It was unknown if patient had acute illnesses at the time of vaccination and up to one month before. Patient's chronic or long-standing health conditions were unknown. On 07-Jun-2022 at 9:39 AM, the patient received first dose of mRNA-1273 (Spikevax) (Intramuscular) .25 milliliter. On 07-Jun-2022 at 9:39 AM, the patient experienced EXPIRED PRODUCT ADMINISTERED (Vaccine was administered on 7 June 2022 after the expiration date of 13 May 2022.) and UNDERDOSE (patient received 0.25 ml as dose 1). On an unknown date, the patient experienced PRODUCT STORAGE ERROR (Vial was expired on 13-May-2022, stored in refrigerator on 21-Jan-2022 and administered on 07-Jun-2022) and NO ADVERSE EVENT (No adverse event). At the time of the report, EXPIRED PRODUCT ADMINISTERED (Vaccine was administered on 7 June 2022 after the expiration date of 13 May 2022.), PRODUCT STORAGE ERROR (Vial was expired on 13-May-2022, stored in refrigerator on 21-Jan-2022 and administered on 07-Jun-2022), UNDERDOSE (patient received 0.25 ml as dose 1) and NO ADVERSE EVENT (No adverse event) outcome was unknown. Not provided. For mRNA-1273 (Spikevax) (Intramuscular), the reporter considered NO ADVERSE EVENT (No adverse event) to be not related and EXPIRED PRODUCT ADMINISTERED (Vaccine was administered on 7 June 2022 after the expiration date of 13 May 2022.) to have an unknown relationship. No further causality assessments were provided for PRODUCT STORAGE ERROR (Vial was expired on 13-May-2022, stored in refrigerator on 21-Jan-2022 and administered on 07-Jun-2022) and UNDERDOSE (patient received 0.25 ml as dose 1). Concomitant medications were not provided by the reporter. The vial did not undergo any temperature excursions. The used vial was placed in the refrigerator on the same day of administration (07-Jun-2022).The reporter thought that Moderna had an extension like Pfizer, and it would expire on the 13-Jul-2022 but it was expired on the 13-May-2022, they realize this on the 08-Jun-2022. Event did not cause the patient to seek medical care. It was unknown if there were any other potential causes and if patient experience similar events in the past. Prescriptions, over-the-counter medications, dietary supplements, or herbal remedies being taken by the patient at time of vaccination and/or at the time of the adverse event was unknown.  Treatment information was not provided. This case was linked to MODERNATX, INC.-MOD-2022-586793 (E2B Linked Report). Sender's Comments: MODERNATX, INC.-MOD-2022-586793:Master case.