No adverse event; The patient as per current guidelines should have received a Moderna bivalent vaccine for a booster dose however the patient received a Pfizer bivalent Moderna Covid-19 vaccine booster dose instead.; The patient as per current guidelines should have received a Moderna bivalent vaccine for a booster dose however the patient received a Pfizer bivalent Moderna Covid-19 vaccine booster dose instead.; This spontaneous case was reported by a nurse and describes the occurrence of INTERCHANGE OF VACCINE PRODUCTS (The patient as per current guidelines should have received a Moderna bivalent vaccine for a booster dose however the patient received a Pfizer bivalent Moderna Covid-19 vaccine booster dose instead.), COVID-19 IMMUNISATION (The patient as per current guidelines should have received a Moderna bivalent vaccine for a booster dose however the patient received a Pfizer bivalent Moderna Covid-19 vaccine booster dose instead.) and NO ADVERSE EVENT (No adverse event) in a 15-month-old male patient who received mRNA-1273 (Spikevax) (batch nos. AR9236B and AR9236B) for COVID-19 prophylaxis.    Co-suspect product included non-company product TOZINAMERAN (PFIZER BIONTECH COVID-19 VACCINE) for an unknown indication.    No Medical History information was reported.   On 15-Dec-2022, the patient received first dose of mRNA-1273 (Spikevax) (unknown route) 1 dosage form. On 13-Jan-2023, received second dose of mRNA-1273 (Spikevax) (unknown route) dosage was changed to 1 dosage form. On 28-Jun-2023, the patient received third dose of TOZINAMERAN (PFIZER BIONTECH COVID-19 VACCINE) (unknown route) 1 dosage form. On 28-Jun-2023, the patient experienced INTERCHANGE OF VACCINE PRODUCTS (The patient as per current guidelines should have received a Moderna bivalent vaccine for a booster dose however the patient received a Pfizer bivalent Moderna Covid-19 vaccine booster dose instead.) and COVID-19 IMMUNISATION (The patient as per current guidelines should have received a Moderna bivalent vaccine for a booster dose however the patient received a Pfizer bivalent Moderna Covid-19 vaccine booster dose instead.). On an unknown date, the patient experienced NO ADVERSE EVENT (No adverse event). At the time of the report, INTERCHANGE OF VACCINE PRODUCTS (The patient as per current guidelines should have received a Moderna bivalent vaccine for a booster dose however the patient received a Pfizer bivalent Moderna Covid-19 vaccine booster dose instead.), COVID-19 IMMUNISATION (The patient as per current guidelines should have received a Moderna bivalent vaccine for a booster dose however the patient received a Pfizer bivalent Moderna Covid-19 vaccine booster dose instead.) and NO ADVERSE EVENT (No adverse event) outcome was unknown.        For mRNA-1273 (Spikevax) (Unknown), the reporter considered NO ADVERSE EVENT (No adverse event) to be not related. No further causality assessments were provided for INTERCHANGE OF VACCINE PRODUCTS (The patient as per current guidelines should have received a Moderna bivalent vaccine for a booster dose however the patient received a Pfizer bivalent Moderna Covid-19 vaccine booster dose instead.) and COVID-19 IMMUNISATION (The patient as per current guidelines should have received a Moderna bivalent vaccine for a booster dose however the patient received a Pfizer bivalent Moderna Covid-19 vaccine booster dose instead.).    Concomitant product use was not provided by the reporter.  Treatment information was not provided.