No adverse event; 11 patients instead of 20 patients who were inadvertently administered with the monovalent vaccine instead of the bivalent booster dose / Patient got Monovalent booster instead of bivalent booster; 0.25 ml received for Dose 2 instead of 0.5 ml; This spontaneous case was reported by a pharmacist and describes the occurrence of WRONG PRODUCT ADMINISTERED (11 patients instead of 20 patients who were inadvertently administered with the monovalent vaccine instead of the bivalent booster dose / Patient got Monovalent booster instead of bivalent booster), UNDERDOSE (0.25 ml received for Dose 2 instead of 0.5 ml) and NO ADVERSE EVENT (No adverse event) in an 84-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. AR6965B and 022A2H) for COVID-19 prophylaxis.     It was unknown if patient was ever diagnosed with or tested positive for COVID-19. It was unknown if patient had acute illness at the time of the vaccination or up to one month before. It was unknown if patient had any chronic or long-standing health conditions.  It was unknown if patient had any prescriptions, over-the counter medications, dietary supplements or herbal remedies taken at the time of the vaccination or at the time of the adverse event.    On 27-Jan-2022 at 10:01 AM, the patient received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) .25 milliliter. On 23-Jan-2023 at 10:14 AM, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to .5 milliliter. On 27-Jan-2022 at 10:01 AM, the patient experienced UNDERDOSE (0.25 ml received for Dose 2 instead of 0.5 ml). On 23-Jan-2023 at 10:14 AM,  after starting mRNA-1273 (Moderna COVID-19 Vaccine), the patient experienced WRONG PRODUCT ADMINISTERED (11 patients instead of 20 patients who were inadvertently administered with the monovalent vaccine instead of the bivalent booster dose / Patient got Monovalent booster instead of bivalent booster). On an unknown date, the patient experienced NO ADVERSE EVENT (No adverse event). At the time of the report, WRONG PRODUCT ADMINISTERED (11 patients instead of 20 patients who were inadvertently administered with the monovalent vaccine instead of the bivalent booster dose / Patient got Monovalent booster instead of bivalent booster), UNDERDOSE (0.25 ml received for Dose 2 instead of 0.5 ml) and NO ADVERSE EVENT (No adverse event) outcome was unknown. Not Provided      For mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular), the reporter considered WRONG PRODUCT ADMINISTERED (11 patients instead of 20 patients who were inadvertently administered with the monovalent vaccine instead of the bivalent booster dose / Patient got Monovalent booster instead of bivalent booster) and NO ADVERSE EVENT (No adverse event) to be not related. No further causality assessment was provided for UNDERDOSE (0.25 ml received for Dose 2 instead of 0.5 ml).    Concomitant medications were not reported.  It was reported that Moderna monovalent vaccine was administered to approximately 20 patients from 11-Jan-2023 to 21-Jan-2023, instead of the Moderna bivalent booster. HCP wanted to know if these patients can receive the Moderna bivalent booster shot after this incorrect dose, and how long should they wait to receive it.  They stated that there were only 11 patients instead of 20 patients who were inadvertently administered with the monovalent vaccine instead of the bivalent booster dose. Patient administered the vaccine at 10:14 am on 23-Jan-2023.  Treatment information was not provided.  This case pertains to 04th of the total 20 patients.   This case was linked to US-MODERNATX, INC.-MOD-2023-704234 (Linked Report).   Most recent FOLLOW-UP information incorporated above includes: On 24-Jan-2023: Follow up received wherein the patient demographics, product and narrative updated. On 25-Jan-2023: Live follow-up document received contains no new information On 06-Feb-2023: Follow-up document received contain no new information. On 06-Feb-2023: Significant follow up received contains route of administration added, event verbatim and narrative updated On 07-Feb-2023: Follow-up document received with no newinformation On 15-Feb-2023: Significant follow-up received contains reporter details added, patient details added, suspect details added, event details and causality updated, narrative updated.; Sender's Comments:  US-MODERNATX, INC.-MOD-2023-704234: case