Relapse. Negative on 5/10, positive again 5/13 with cold symptoms; Patient received Pfizer vaccine before Moderna vaccine; This spontaneous case was reported by a patient and describes the occurrence of COVID-19 (Relapse. Negative on 5/10, positive again 5/13 with cold symptoms) and INTERCHANGE OF VACCINE PRODUCTS (Patient received Pfizer vaccine before Moderna vaccine) in a 46-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 (Location of injection: Left Arm  and Vaccine Administration Time: 12:00 PM) on 30-Jun-2021. Past adverse reactions to the above products included No adverse event with Pfizer / BioNTech. Concurrent medical conditions included Obesity.    On 19-Jan-2022 at 12:00 PM, the patient received dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 19-Jan-2022, the patient experienced INTERCHANGE OF VACCINE PRODUCTS (Patient received Pfizer vaccine before Moderna vaccine). On 13-May-2022, the patient experienced COVID-19 (Relapse. Negative on 5/10, positive again 5/13 with cold symptoms). The patient was treated with NIRMATRELVIR, RITONAVIR (PAXLOVID) from 04-May-2022 to 09-May-2022 for COVID-19 treatment, at an unspecified dose and frequency. At the time of the report, COVID-19 (Relapse. Negative on 5/10, positive again 5/13 with cold symptoms) had not resolved and INTERCHANGE OF VACCINE PRODUCTS (Patient received Pfizer vaccine before Moderna vaccine) outcome was unknown. Not Provided    DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 10-May-2022, SARS-CoV-2 test: negative (Negative) Negative. On 13-May-2022, SARS-CoV-2 test: positive (Positive) Positive.         No concomitant medication information was provided. No known allergy were reported. Device date:14-May-2022  Company Comment: This spontaneous case of Interchange of vaccine products, concerns a 46-year-old female patient, with a relevant medical history of Obesity and previous vaccination of Pfizer/BioNTech vaccine, who experienced the unexpected AESI of COVID-19. The event occurred approximately 3 months after receiving a dose of mRNA-1273 Vaccine. The patient was treated with NIRMATRELVIR, RITONAVIR (PAXLOVID) for COVID-19, however the patient had cold symptoms and tested positive again after 4 days of treatment. The outcome of the event was reported as not resolved. The patient's medical history of Obesity and previous vaccination of Pfizer/BioNTech vaccine, remain as confounders for the occurrence of the event. The benefit-risk relationship of mRNA-1273 Vaccine is not affected by this report.; Sender's Comments: This spontaneous case of Interchange of vaccine products, concerns a 46-year-old female patient, with a relevant medical history of Obesity and previous vaccination of Pfizer/BioNTech vaccine, who experienced the unexpected AESI of COVID-19. The event occurred approximately 3 months after receiving a dose of mRNA-1273 Vaccine. The patient was treated with NIRMATRELVIR, RITONAVIR (PAXLOVID) for COVID-19, however the patient had cold symptoms and tested positive again after 4 days of treatment. The outcome of the event was reported as not resolved. The patient's medical history of Obesity and previous vaccination of Pfizer/BioNTech vaccine, remain as confounders for the occurrence of the event. The benefit-risk relationship of mRNA-1273 Vaccine is not affected by this report.