This spontaneous case was reported by a patient and describes the occurrence of COVID-19 (After 5 day course of Paxlovid tested positive for Covid on day 7) and INTERCHANGE OF VACCINE PRODUCTS (Interchange of vaccine products) in a 66-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 065k21a) for COVID-19 treatment. Co-suspect product included non-company product NIRMATRELVIR, RITONAVIR (PAXLOVID) for an unknown indication. Previously administered products included for Product used for unknown indication: Pfizer / BioNTech (Dose number: 1, batch/Lot No: ER8729, location of injection: arm right and vaccine administration time: 02:00 PM) on 10-Apr-2021, Pfizer / BioNTech (Dose number: 2, batch/Lot No: EW0170, location of injection: arm right and vaccine administration time: 01:00 PM) on 01-May-2021, Pfizer / BioNTech (Dose number: 3, batch/Lot No: FG3527 and location of injection: arm right and vaccine administration time: 03:00 PM) on 04-Nov-2021. Past adverse reactions to the above products included No adverse event with Pfizer / BioNTech, Pfizer / BioNTech and Pfizer / BioNTech. Concurrent medical conditions included Penicillin allergy. On 12-Apr-2022, the patient received fourth dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. In June 2022, the patient started NIRMATRELVIR, RITONAVIR (PAXLOVID) (unknown route) at an unspecified dose. On 02-Jul-2022, the patient experienced INTERCHANGE OF VACCINE PRODUCTS (Interchange of vaccine products). On 02-Jul-2022 at 4:00 PM, after starting mRNA-1273 (Moderna COVID-19 Vaccine), the patient experienced COVID-19 (After 5 day course of Paxlovid tested positive for Covid on day 7). At the time of the report, COVID-19 (After 5 day course of Paxlovid tested positive for Covid on day 7) and INTERCHANGE OF VACCINE PRODUCTS (Interchange of vaccine products) outcome was unknown. Not Provided. DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, SARS-CoV-2 test: (Positive) Positive. The patient was not taking any other medications/products (concomitant) within 2 weeks of starting COVID-19 treatment. Treatment received for event was reported as no. Company comment: This Spontaneous case reported by a patient concerns a 66-year-old, male patient with no relevant medical history reported, who experienced the unexpected, non serious AESI of COVID-19 (After 5 day course of Paxlovid tested positive for Covid on day 7) about 2 months and 20 days after receiving the 4 dose of mRNA1273 Vaccine in the Covid 19 vaccination series. Patient previously received the 2 primary doses and the 3 dose with Pfizer vaccines, with no adverse events reported for Pfizer vaccines. Interchange of vaccine products was noted. No details on symptoms, comorbidities, other labs and diagnostic tests, and treatment details was provided. In June 2022, the patient was started on Nirmatrelvir, Ritonavir (PAXLOVID) at an unspecified dose, for an unknown indication. On 02-Jul-2022 patient experienced COVID-19. After 5 day course of Paxlovid, he was tested positive for Covid on day 7. On an unknown date SARS-CoV-2 test was positive. No treatment was received for the event. The event outcome was unknown. Ongoing Covid 19 pandemia and use of Paxlovid remain as confounders. The benefit-risk relationship of mRNA-1273 is not affected by this report. Events´ seriousness assessed as per medical judgement. Sender's Comments: This Spontaneous case reported by a patient concerns a 66-year-old, male patient with no relevant medical history reported, who experienced the unexpected, non serious AESI of COVID-19 (After 5 day course of Paxlovid tested positive for Covid on day 7) about 2 months and 20 days after receiving the 4 dose of mRNA1273 Vaccine in the Covid 19 vaccination series. Patient previously received the 2 primary doses and the 3 dose with Pfizer vaccines, with no adverse events reported for Pfizer vaccines. Interchange of vaccine products was noted. No details on symptoms, comorbidities, other labs and diagnostic tests, and treatment details was provided. In June 2022, the patient was started on Nirmatrelvir, Ritonavir (PAXLOVID) at an unspecified dose, for an unknown indication. On 02-Jul-2022 patient experienced COVID-19. After 5 day course of Paxlovid, he was tested positive for Covid on day 7. On an unknown date SARS-CoV-2 test was positive. No treatment was received for the event. The event outcome was unknown. Ongoing Covid 19 pandemia and use of Paxlovid remain as confounders. The benefit-risk relationship of mRNA-1273 is not affected by this report. Events´ seriousness assessed as per medical judgement.