Clostridium difficile infection; This spontaneous case was reported by a consumer and describes the occurrence of CLOSTRIDIUM DIFFICILE INFECTION (Clostridium difficile infection) in a 73-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination.    Co-suspect product included non-company product ADALIMUMAB (HUMIRA) solution for injection for Crohn's disease.    No Medical History information was reported.   On 19-Jan-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 16-Feb-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On 16-Aug-2021, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On an unknown date, the patient started ADALIMUMAB (HUMIRA) (Subcutaneous) at an unspecified dose. In September 2021, the patient experienced CLOSTRIDIUM DIFFICILE INFECTION (Clostridium difficile infection) (seriousness criterion medically significant). At the time of the report, CLOSTRIDIUM DIFFICILE INFECTION (Clostridium difficile infection) outcome was unknown.        The action taken with mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) was unknown.       No concomitant medications were reported. No treatment medication was reported.  This case was identified as part of a retrospective clean-up activity where certain emails received in the Moderna mailbox were missed to be booked-in.  Company Comment: This spontaneous case concerns a 73-year-old, female patient with history of co-suspect administration of Humira (adalimumab) for Moderate-to-severe Crohn's disease, who experienced the unexpected, serious (medically significant) event of clostridium difficile infection. The event occurred unknown number of days after receiving Humira and unknown number of days after receiving the third (booster) dose of the mRNA-1273 vaccine. Of note, the administration date of Humira was not provided and the event onset date was reported as unspecified date in Sep2021, hence, the onset latency could not be assessed. Treatment information was not provided. The outcome of the event was unknown at the time of the report. The co-suspect product Humira, a tumor necrosis factor-alpha blocker that can lower the ability of the immune system to fight infections, remains a confounder. The patient's advanced age (high risk for infections) also remains a confounder. The benefit-risk relationship of the mRNA-1273 vaccine is not affected by this report.   This case was linked to MOD-2022-623881 (Patient Link).; Sender's Comments: This spontaneous case concerns a 73-year-old, female patient with history of co-suspect administration of Humira (adalimumab) for Moderate-to-severe Crohn's disease, who experienced the unexpected, serious (medically significant) event of clostridium difficile infection. The event occurred unknown number of days after receiving Humira and unknown number of days after receiving the third (booster) dose of the mRNA-1273 vaccine. Of note, the administration date of Humira was not provided and the event onset date was reported as unspecified date in Sep2021, hence, the onset latency could not be assessed. Treatment information was not provided. The outcome of the event was unknown at the time of the report. The co-suspect product Humira, a tumor necrosis factor-alpha blocker that can lower the ability of the immune system to fight infections, remains a confounder. The patient's advanced age (high risk for infections) also remains a confounder. The benefit-risk relationship of the mRNA-1273 vaccine is not affected by this report.