A nurse and medical assistant administered a vaccine (a total of 6 patients) past the use by day of a thawed vial. The use-by date was the 28-May-2023 and were administered on the 31-May-2023/She reports that at least six doses were administered; No adverse event; This spontaneous case was reported by an other health care professional and describes the occurrence of EXPIRED PRODUCT ADMINISTERED (A nurse and medical assistant administered a vaccine (a total of 6 patients) past the use by day of a thawed vial. The use-by date was the 28-May-2023 and were administered on the 31-May-2023/She reports that at least six doses were administered) and NO ADVERSE EVENT (No adverse event) in an adult patient of an unknown gender who received mRNA-1273 BIVALENT .222 (MODERNA COVID-19 VACCINE, BIVALENT (ORIGINAL AND OMICRON BA.4/BA.5)) (batch no. 066H22A) for COVID-19 prophylaxis.     No Medical History information was reported.    On an unknown date, the patient received dose of mRNA-1273 BIVALENT .222 (MODERNA COVID-19 VACCINE, BIVALENT (ORIGINAL AND OMICRON BA.4/BA.5)) (unknown route) .5 milliliter. On an unknown date, the patient experienced EXPIRED PRODUCT ADMINISTERED (A nurse and medical assistant administered a vaccine (a total of 6 patients) past the use by day of a thawed vial. The use-by date was the 28-May-2023 and were administered on the 31-May-2023/She reports that at least six doses were administered) and NO ADVERSE EVENT (No adverse event). At the time of the report, EXPIRED PRODUCT ADMINISTERED (A nurse and medical assistant administered a vaccine (a total of 6 patients) past the use by day of a thawed vial. The use-by date was the 28-May-2023 and were administered on the 31-May-2023/She reports that at least six doses were administered) and NO ADVERSE EVENT (No adverse event) outcome was unknown.        For mRNA-1273 BIVALENT .222 (MODERNA COVID-19 VACCINE, BIVALENT (ORIGINAL AND OMICRON BA.4/BA.5)) (Unknown), the reporter considered NO ADVERSE EVENT (No adverse event) to be not related. No further causality assessment was provided for EXPIRED PRODUCT ADMINISTERED (A nurse and medical assistant administered a vaccine (a total of 6 patients) past the use by day of a thawed vial. The use-by date was the 28-May-2023 and were administered on the 31-May-2023/She reports that at least six doses were administered).    No concomitant medications were reported.  It was reported that a nurse and medical assistant administered a vaccine (a total of 6 patients) past the use by day of a thawed vial. The use-by date was the 28-May-2023. No current side effects have been reported back to the office. It was reported that the Moderna Bivalent vaccine was administered of 0.5 ml for 5 adults and a 0.25 ml for a child. The HCP reported that some expired doses were also administered on 30-May-2023, but for now, they know for sure that there were 6 patients involved on 31-May-2023. It was reported that the vial size was 2.5 ml. On 28-Apr-2023, the vial was initially stored in the refrigerator. The date of administration of vaccine was reported as 30-May-2023 and 31-May-2023.  Treatment information was not provided.   This case was linked to US-MODERNATX, INC.-MOD-2023-727180 (E2B Linked Report).   Most recent FOLLOW-UP information incorporated above includes: On 31-May-2023: Live Significant follow-up appended: Suspect product details updated and narrative updated.; Sender's Comments:  US-MODERNATX, INC.-MOD-2023-727180:Master Case