Received 0.25ml of Bivalent booster instead of 0.5 ml; No adverse event; This spontaneous case was reported by an other health care professional and describes the occurrence of ACCIDENTAL UNDERDOSE (Received 0.25ml of Bivalent booster instead of 0.5 ml) 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)) for COVID-19 vaccination.     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) .25 milliliter. On an unknown date, the patient experienced ACCIDENTAL UNDERDOSE (Received 0.25ml of Bivalent booster instead of 0.5 ml) and NO ADVERSE EVENT (No adverse event). At the time of the report, ACCIDENTAL UNDERDOSE (Received 0.25ml of Bivalent booster instead of 0.5 ml) 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 ACCIDENTAL UNDERDOSE (Received 0.25ml of Bivalent booster instead of 0.5 ml).    This case contains information for the 7th of 20 adult patients described by the reporter. No concomitant medications were provided. Product start date was from 01Sep2022 to 26-Oct-2022. No treatment medications were reported.   This case was linked to US-MODERNATX, INC.-MOD-2022-665399, US-MODERNATX, INC.-MOD-2022-665435, US-MODERNATX, INC.-MOD-2022-665436, US-MODERNATX, INC.-MOD-2022-665437, US-MODERNATX, INC.-MOD-2022-665466, US-MODERNATX, INC.-MOD-2022-665472, US-MODERNATX, INC.-MOD-2022-665480, US-MODERNATX, INC.-MOD-2022-665491, US-MODERNATX, INC.-MOD-2022-665494, US-MODERNATX, INC.-MOD-2022-665504, US-MODERNATX, INC.-MOD-2022-665519, US-MODERNATX, INC.-MOD-2022-665541, US-MODERNATX, INC.-MOD-2022-665611, US-MODERNATX, INC.-MOD-2022-665613, US-MODERNATX, INC.-MOD-2022-665659, US-MODERNATX, INC.-MOD-2022-665669, US-MODERNATX, INC.-MOD-2022-665686, US-MODERNATX, INC.-MOD-2022-665696, US-MODERNATX, INC.-MOD-2022-665705 (E2B Linked Report).; Sender's Comments:  US-MODERNATX, INC.-MOD-2022-665399:Same reporter US-MODERNATX, INC.-MOD-2022-665435:Same reporter US-MODERNATX, INC.-MOD-2022-665436:Same reporter US-MODERNATX, INC.-MOD-2022-665437:Same reporter US-MODERNATX, INC.-MOD-2022-665466:Same reporter US-MODERNATX, INC.-MOD-2022-665472:Same reporter US-MODERNATX, INC.-MOD-2022-665480:Same reporter US-MODERNATX, INC.-MOD-2022-665491:Same reporter US-MODERNATX, INC.-MOD-2022-665494:Same reporter US-MODERNATX, INC.-MOD-2022-665504:Same reporter US-MODERNATX, INC.-MOD-2022-665519:Same reporter US-MODERNATX, INC.-MOD-2022-665541:Same reporter US-MODERNATX, INC.-MOD-2022-665611:Same reporter US-MODERNATX, INC.-MOD-2022-665613:Same reporter US-MODERNATX, INC.-MOD-2022-665659:Same reporter US-MODERNATX, INC.-MOD-2022-665669:Same reporter US-MODERNATX, INC.-MOD-2022-665686:Same reporter US-MODERNATX, INC.-MOD-2022-665696:Same reporter US-MODERNATX, INC.-MOD-2022-665705:Same reporter