Patient did not experience any reaction following the Moderna bivalent booster; Patient received 3 Pfizer monovalent vaccines and then Moderna bivalent booster; Patient received 3 Pfizer monovalent vaccines and then Moderna bivalent booster; This spontaneous case was reported by a patient family member or friend and describes the occurrence of INTERCHANGE OF VACCINE PRODUCTS (Patient received 3 Pfizer monovalent vaccines and then Moderna bivalent booster), COVID-19 IMMUNISATION (Patient received 3 Pfizer monovalent vaccines and then Moderna bivalent booster) and NO ADVERSE EVENT (Patient did not experience any reaction following the Moderna bivalent booster) in a 2-year-old female patient who received mRNA-1273 BIVALENT .222 (MODERNA COVID-19 VACCINE, BIVALENT (ORIGINAL AND OMICRON BA.4/BA.5)) (batch no. ASKU) for COVID-19 prophylaxis.     Previously administered products included for COVID-19 prophylaxis: PFIZER BIONTECH COVID-19 VACCINE on 11-Jul-2022, PFIZER BIONTECH COVID-19 VACCINE on 08-Aug-2022 and PFIZER BIONTECH COVID-19 VACCINE on 04-Oct-2022; for Drug use for unknown indication: Flu shot on 20-Jan-2023. Past adverse reactions to the above products included No adverse event with Flu shot, PFIZER BIONTECH COVID-19 VACCINE, PFIZER BIONTECH COVID-19 VACCINE and PFIZER BIONTECH COVID-19 VACCINE. Concurrent medical conditions included Irritable bowel syndrome.  On 20-Jan-2023, the patient received dose of mRNA-1273 BIVALENT .222 (MODERNA COVID-19 VACCINE, BIVALENT (ORIGINAL AND OMICRON BA.4/BA.5)) (unknown route) 1 dosage form. On 20-Jan-2023, the patient experienced INTERCHANGE OF VACCINE PRODUCTS (Patient received 3 Pfizer monovalent vaccines and then Moderna bivalent booster) and COVID-19 IMMUNISATION (Patient received 3 Pfizer monovalent vaccines and then Moderna bivalent booster). On an unknown date, the patient experienced NO ADVERSE EVENT (Patient did not experience any reaction following the Moderna bivalent booster). At the time of the report, INTERCHANGE OF VACCINE PRODUCTS (Patient received 3 Pfizer monovalent vaccines and then Moderna bivalent booster), COVID-19 IMMUNISATION (Patient received 3 Pfizer monovalent vaccines and then Moderna bivalent booster) and NO ADVERSE EVENT (Patient did not experience any reaction following the Moderna bivalent booster) 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 (Patient did not experience any reaction following the Moderna bivalent booster) to be not related. No further causality assessments were provided for INTERCHANGE OF VACCINE PRODUCTS (Patient received 3 Pfizer monovalent vaccines and then Moderna bivalent booster) and COVID-19 IMMUNISATION (Patient received 3 Pfizer monovalent vaccines and then Moderna bivalent booster).    No concomitant and treatment medications were reported.  The patient had already received 3 Pfizer monovalent vaccines. Patient pediatrician recommended getting the bivalent booster, not realizing that not supposed to give the Moderna bivalent after the 3 doses of Pfizer. The patient did not experience any reaction following the Moderna bivalent booster.