triple positive metastatic ductal carcinoma; Dose Number: 1 Date administered: 13Oct2021 Dose Number: 2 Date administered: 31Jan2022; This spontaneous case was reported by a patient and describes the occurrence of TRIPLE POSITIVE BREAST CANCER (triple positive metastatic ductal carcinoma) in a 46-year-old female patient who received mRNA-1273 (Spikevax) (batch no. 007J21-2A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     The patient had no risk factors. she was not on menopause, she breastfed her children, she did not take hormone medications or birth control, she did a genetic test which said she had no risk factors. So she should not have any breast cancer.  Concomitant products included ONDANSETRON (ZOFRAN [ONDANSETRON]) and PROCHLORPERAZINE MALEATE (COMPAZINE [PROCHLORPERAZINE MALEATE]) for an unknown indication.    On 31-Jan-2022, the patient received second dose of mRNA-1273 (Spikevax) (unknown route) 1 dosage form. On 31-Jan-2022, the patient experienced INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION (Dose Number: 1 Date administered: 13Oct2021 Dose Number: 2 Date administered: 31Jan2022). In July 2022, the patient experienced TRIPLE POSITIVE BREAST CANCER (triple positive metastatic ductal carcinoma) (seriousness criterion medically significant). At the time of the report, TRIPLE POSITIVE BREAST CANCER (triple positive metastatic ductal carcinoma) and INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION (Dose Number: 1 Date administered: 13Oct2021 Dose Number: 2 Date administered: 31Jan2022) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): In December 2020, Mammogram: it was perfect. In July 2022, Mammogram: diagnosed with triple positive metastatic ductal carcinoma.         On 13-Oct-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 vaccine) (unknown route) 1 dosage form (batch no. 050E21A) for COVID-19 vaccination.The patient reported that her family dynamics had changed. The doctors told the patient that there was an anomaly. and the patients surgeon would perform a double mastectomy. The patient reported that her quality of life has changed. she is not on menopause, she breastfed her children. she did a genetic test which said she had no risk factors.  The patient was currently on chemotherapy.  Company comment: This spontaneous case concerns a 46 year old female without a reported medical history who experienced the unexpected, serious (medically significant) event of triple positive breast cancer described as triple positive metastatic ductal carcinoma which occurred approximately 5 months after receiving a dose of mRNA1273 as second dose of COVID-19 vaccine. Latency cannot be fully established since the exact onset date was not specified. The patient received the 2 dose primary series at 110 days interval which is not in alignment with the recommended dosing schedule. The patient was diagnosed with triple positive metastatic ductal carcinoma post vaccination. The patient's surgeon advised double mastectomy for the condition and she is currently on chemotherapy. Further details regarding the clinical course and treatment regimen were not provided. Information regarding other COVID-19 vaccine were not mentioned. The benefit-risk relationship of mRNA-1273 is not affected by this report.; Sender's Comments: This spontaneous case concerns a 46 year old female without a reported medical history who experienced the unexpected, serious (medically significant) event of triple positive breast cancer described as triple positive metastatic ductal carcinoma which occurred approximately 5 months after receiving a dose of mRNA1273 as second dose of COVID-19 vaccine. Latency cannot be fully established since the exact onset date was not specified. The patient received the 2 dose primary series at 110 days interval which is not in alignment with the recommended dosing schedule. The patient was diagnosed with triple positive metastatic ductal carcinoma post vaccination. The patient's surgeon advised double mastectomy for the condition and she is currently on chemotherapy. Further details regarding the clinical course and treatment regimen were not provided. Information regarding other COVID-19 vaccine were not mentioned. The benefit-risk relationship of mRNA-1273 is not affected by this report.