COVID-19 infection; Interchange of vaccine products; This spontaneous case was reported by a patient and describes the occurrence of COVID-19 (COVID-19 infection) and INTERCHANGE OF VACCINE PRODUCTS (Interchange of vaccine products) in a 67-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination.     Previously administered products included for product used for unknown indication: Pfizer / BioNTech (Dose Number: 1 Batch/Lot No: Unknown. Not available/provided to reporter at the time of report completion Location of injection: Arm Left Vaccine Administration Time: 12:00 PM) on 10-Feb-2021, Pfizer / BioNTech (Dose Number: 2 Batch/Lot No: EN6198 Location of injection: Arm Left Vaccine Administration Time: 12:00 PM) on 03-Mar-2021 and Pfizer / BioNTech (Dose Number: 3 Batch/Lot No: 301358 Location of injection: Arm Left Vaccine Administration Time: 12:00 PM) on 29-Sep-2021. Past adverse reactions to the above products included No adverse event with Pfizer / BioNTech, Pfizer / BioNTech and Pfizer / BioNTech. Concurrent medical conditions included Osteoporosis.    On 03-Mar-2022 at 2:00 PM, the patient received fourth dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 03-Mar-2022, the patient experienced INTERCHANGE OF VACCINE PRODUCTS (Interchange of vaccine products). In May 2022, the patient experienced COVID-19 (COVID-19 infection). The patient was treated with NIRMATRELVIR, RITONAVIR (PAXLOVID) from 16-May-2022 to 21-May-2022 for COVID-19 treatment, at an unspecified dose and frequency. At the time of the report, COVID-19 (COVID-19 infection) was resolving and INTERCHANGE OF VACCINE PRODUCTS (Interchange of vaccine products) outcome was unknown.            Concomitant product use was not provided by the reporter. It was reported that patient was taking an unspecified drug which caused allergy. The patient was not taking any other medications/products within 2 weeks of starting COVID-19 treatment. Device date was reported as 28-May-2022.  Company comment:  This spontaneous case concerns a 67-year-old female patient with no relevant medical history reported, who experienced the unexpected non-serious adverse event of special interest COVID-19, that occurred approximately 2.5 months after receiving mRNA-1273 given as fourth dose in the COVID-19 vaccination series. Patient completed a 6-day course of Nirmatrelvir, Ritonavir (Paxlovid) COVID-19 treatment and presented with COVID-19 rebound symptoms 5 days later.  Patient previously received 3 doses of COVID-19 vaccine from non-company brand Pfizer/ BioNTech, the last dose of which was given 5 months and 2 days prior to mRNA-1273 vaccine. Elderly age of the patient and the ongoing COVID-19 pandemic could be considered as risk factors for the event. The benefit-risk relationship of mRNA-1273 is not affected by this report. Sender's Comments: This spontaneous case concerns a 67-year-old female patient with no relevant medical history reported, who experienced the unexpected non-serious adverse event of special interest COVID-19, that occurred approximately 2.5 months after receiving mRNA-1273 given as fourth dose in the COVID-19 vaccination series. Patient completed a 6-day course of Nirmatrelvir, Ritonavir (Paxlovid) COVID-19 treatment and presented with COVID-19 rebound symptoms 5 days later.  Patient previously received 3 doses of COVID-19 vaccine from non-company brand Pfizer/ BioNTech, the last dose of which was given 5 months and 2 days prior to mRNA-1273 vaccine. Elderly age of the patient and the ongoing COVID-19 pandemic could be considered as risk factors for the event. The benefit-risk relationship of mRNA-1273 is not affected by this report.