Interchange of vaccine products; Patient began testing positive again and experiencing moderate symptoms 5 days after taking last dose of Plaxovid; This spontaneous case was reported by a consumer and describes the occurrence of COVID-19 (Patient began testing positive again and experiencing moderate symptoms 5 days after taking last dose of Plaxovid) and INTERCHANGE OF VACCINE PRODUCTS (Interchange of vaccine products) in a 38-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination.    Co-suspect product included non-company product NIRMATRELVIR, RITONAVIR (PAXLOVID) for COVID-19 treatment.    It was unknown whether the patient was taking any other medications/products within 2 weeks of starting COVID-19 treatment.  The patient had previously received a COVID-19 Vaccine.  Previously administered products included for Product used for unknown indication: Pfizer / BioNTech (Dose Number: 1 Batch/Lot No: EN6208 Location of injection: Arm Left) on 16-Mar-2021 and Pfizer / BioNTech (Dose Number: 2 Batch/Lot No: ER8737 Location of injection: Arm Left) on 06-Apr-2021. Past adverse reactions to the above products included No adverse event with Pfizer / BioNTech and Pfizer / BioNTech. Concurrent medical conditions included Allergy and Asthma.   On 12-Nov-2021, the patient received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 01-May-2022, the patient started NIRMATRELVIR, RITONAVIR (PAXLOVID) (unknown route) at an unspecified dose. On 11-May-2022 at 8:00 AM, the patient experienced COVID-19 (Patient began testing positive again and experiencing moderate symptoms 5 days after taking last dose of Plaxovid). On an unknown date, the patient experienced INTERCHANGE OF VACCINE PRODUCTS (Interchange of vaccine products). At the time of the report, COVID-19 (Patient began testing positive again and experiencing moderate symptoms 5 days after taking last dose of Plaxovid) had not resolved and INTERCHANGE OF VACCINE PRODUCTS (Interchange of vaccine products) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 11-May-2022, SARS-CoV-2 test: positive (Positive) Positive.         No concomitant medications were reported. The patient had medical consultation and OTC therapies. Device Date was reported as 13May-2022.  Company Comment: This spontaneous case of Interchange of vaccine products, concerns a 38-year-old male patient, with primary vaccinations of Pfizer/ BioNTech for COVID-19 and co-suspect product Paxlovid for COVID-19 treatment, who experienced the unexpected AESI of COVID-19. The event occurred approximately 5 months and 19 days after receiving the third dose of mRNA-1273 Vaccine. The patient was treated with NIRMATRELVIR, RITONAVIR (PAXLOVID) for COVID-19, however the patient started experiencing moderate symptoms 5 days after taking the last dose of Plaxovid. The outcome of the event was reported as unknown. The patient's medical history of primary vaccinations of Pfizer / BioNTech for COVID-19 and co-suspect product Paxlovid for COVID-19 treatment, 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 38-year-old male patient, with primary vaccinations of Pfizer/ BioNTech for COVID-19 and co-suspect product Paxlovid for COVID-19 treatment, who experienced the unexpected AESI of COVID-19. The event occurred approximately 5 months and 19 days after receiving the third dose of mRNA-1273 Vaccine. The patient was treated with NIRMATRELVIR, RITONAVIR (PAXLOVID) for COVID-19, however the patient started experiencing moderate symptoms 5 days after taking the last dose of Plaxovid. The outcome of the event was reported as unknown. The patient's medical history of primary vaccinations of Pfizer / BioNTech for COVID-19 and co-suspect product Paxlovid for COVID-19 treatment, remain as confounders for the occurrence of the event. The benefit-risk relationship of mRNA-1273 Vaccine is not affected by this report.