Interchange of vaccine products; COVID-19 infection prior to Paxlovid treatment; This spontaneous case was reported by a consumer and describes the occurrence of COVID-19 (COVID-19 infection prior to Paxlovid treatment) and INTERCHANGE OF VACCINE PRODUCTS (Interchange of vaccine products) in an adult female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 022L21A and 017F21A) for COVID-19 vaccination.     Previously administered products included for Product used for unknown indication: Pfizer / BioNTech (Dose Number: 1 Batch/Lot No: EN6199 Location of injection: Arm Left) on 08-Mar-2021 and Pfizer / BioNTech (Dose Number: 2  Batch/Lot No: ER2613  Location of injection: Arm Left) on 29-Mar-2021. Past adverse reactions to the above products included No adverse reaction with Pfizer / BioNTech and Pfizer / BioNTech. Concurrent medical conditions included Drug allergy.   On 28-Oct-2021, the patient received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 05-Apr-2022, received fourth dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. In May 2022, the patient experienced COVID-19 (COVID-19 infection prior to Paxlovid treatment). On an unknown date, the patient experienced INTERCHANGE OF VACCINE PRODUCTS (Interchange of vaccine products). The patient was treated with NIRMATRELVIR, RITONAVIR (PAXLOVID) from 18-May-2022 to 22-May-2022 for COVID-19 treatment, at an unspecified dose and frequency. At the time of the report, COVID-19 (COVID-19 infection prior to Paxlovid treatment) and INTERCHANGE OF VACCINE PRODUCTS (Interchange of vaccine products) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 28-May-2022, SARS-CoV-2 test: positive (Positive) positive. On an unknown date, SARS-CoV-2 test: negative (Negative) negative.         No concomitant medications were reported.  It was reported that patient had taken any other medications/products within 2 weeks of starting COVID-19 treatment.   Company Comment:  This spontaneous case concerns an adult female patient of unknown age with no relevant medical history reported, who experienced the unexpected non-serious adverse event of special interest COVID-19, that occurred approximately 5 weeks after receiving mRNA-1273 given as fourth dose in the COVID-19 vaccination series. Patient underwent a 5-day-course of Nirmatrelvir, Ritonavir (Paxlovid) COVID-19 treatment and tested negative subsequently. Six days later, patient presented with return of COVID-19 symptom reported as congestion and a positive SARS-CoV-2 test. Patient previously received a 2-dose primary series of COVID-19 vaccines from non-company brand Pfizer/ BioNTech, followed by mRNA-1273 vaccine given as third dose. The benefit-risk relationship of mRNA-1273 is not affected by this report.; Sender's Comments: This spontaneous case concerns an adult female patient of unknown age with no relevant medical history reported, who experienced the unexpected non-serious adverse event of special interest COVID-19, that occurred approximately 5 weeks after receiving mRNA-1273 given as fourth dose in the COVID-19 vaccination series.  Patient underwent a 5-day-course of Nirmatrelvir, Ritonavir (Paxlovid) COVID-19 treatment and tested negative subsequently. Six days later, patient presented with return of COVID-19 symptom reported as congestion and a positive SARS-CoV-2 test. Patient previously received a 2-dose primary series of COVID-19 vaccines from non-company brand Pfizer/ BioNTech, followed by mRNA-1273 vaccine given as third dose. The benefit-risk relationship of mRNA-1273 is not affected by this report.