No adverse event; Dose/ Volume 0.2 Given for Dose 2; Vaccine that underwent temperature excursions could have been administered to patient; Vaccine that underwent temperature excursions could have been administered to patient/ Refridgeration excursions identified; This spontaneous case was reported by a nurse and describes the occurrence of PRODUCT TEMPERATURE EXCURSION ISSUE (Vaccine that underwent temperature excursions could have been administered to patient/ Refridgeration excursions identified), ACCIDENTAL UNDERDOSE (Dose/ Volume 0.2 Given for Dose 2), POOR QUALITY PRODUCT ADMINISTERED (Vaccine that underwent temperature excursions could have been administered to patient) and NO ADVERSE EVENT (No adverse event) in a 3-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. AS1412B) for COVID-19 prophylaxis.     It was unknown if patient was ever been diagnosed with/ tested positive for COVID-19.     On 27-Aug-2022 at 2:15 PM, the patient received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) .2 milliliter. In August 2022, the patient experienced PRODUCT TEMPERATURE EXCURSION ISSUE (Vaccine that underwent temperature excursions could have been administered to patient/ Refridgeration excursions identified). On 27-Aug-2022 at 2:15 PM, the patient experienced ACCIDENTAL UNDERDOSE (Dose/ Volume 0.2 Given for Dose 2) and POOR QUALITY PRODUCT ADMINISTERED (Vaccine that underwent temperature excursions could have been administered to patient). On an unknown date, the patient experienced NO ADVERSE EVENT (No adverse event). At the time of the report, PRODUCT TEMPERATURE EXCURSION ISSUE (Vaccine that underwent temperature excursions could have been administered to patient/ Refridgeration excursions identified), ACCIDENTAL UNDERDOSE (Dose/ Volume 0.2 Given for Dose 2), POOR QUALITY PRODUCT ADMINISTERED (Vaccine that underwent temperature excursions could have been administered to patient) and NO ADVERSE EVENT (No adverse event) outcome was unknown.        For mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular), the reporter considered NO ADVERSE EVENT (No adverse event) to be not related. No further causality assessments were provided for PRODUCT TEMPERATURE EXCURSION ISSUE (Vaccine that underwent temperature excursions could have been administered to patient/ Refridgeration excursions identified), ACCIDENTAL UNDERDOSE (Dose/ Volume 0.2 Given for Dose 2) and POOR QUALITY PRODUCT ADMINISTERED (Vaccine that underwent temperature excursions could have been administered to patient).    The Nurse reported that temperature excursion had occurred in a refrigerator at her clinic containing both monovalent and bivalent Moderna COVID-19 vaccines. The Moderna and Bivalent vaccines had undergone several temperature excursions and may have been administered to the patients.   The vaccines were stored in the Refrigerator. There were 2 unbroken cartons with 20 vials. The vials of both monovalent vaccines were moved from freezer to refrigerator on 07-Sep-2022. All the vials were not visualized. The patient administered the vaccine in the deltoid (unspecified location) muscle.  It was reported that refrigeration excursions identified, state vaccine was housed in these units.There were excursions noted. No adverse reactions were reported.   No concomitant medication reported. No treatment medication reported.