Rebound of COVID symptoms and positivity 10 days afer the first day of treatment; This spontaneous case was reported by a patient and describes the occurrence of COVID-19 (Rebound of COVID symptoms and positivity 10 days afer the first day of treatment) in a 46-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.    Previously administered products included for Product used for unknown indication: Johnson and Johnson (Location of injection: left arm) on 15-Apr-2021. Past adverse reactions to the above products included No adverse event with Johnson and Johnson. Concurrent medical conditions included Drug allergy.   On 10-Nov-2021, the patient received dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 15-May-2022, the patient started NIRMATRELVIR, RITONAVIR (PAXLOVID) (unknown route) at an unspecified dose. On 23-May-2022 at 11:00 PM, the patient experienced COVID-19 (Rebound of COVID symptoms and positivity 10 days afer the first day of treatment). At the time of the report, COVID-19 (Rebound of COVID symptoms and positivity 10 days afer the first day of treatment) was resolving.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 23-May-2022, SARS-CoV-2 test: positivity (Positive) Positivity.         No concomitant medication was reported by reporter.  Patient had not taken any medications within 2 weeks of starting Paxlovid.  No treatment medication was reported by reporter.  Company comment: This is a spontaneous case concerning a 46-years-old male patient with no relevant medical history, who experienced the unexpected non-serious adverse events of special interest, COVID-19 (COVID-19) which occurred 6 months 13 days after receiving a dose of mRNA-1273 vaccine (dose number not specified). The event COVID-19 was reported as; Rebound of COVID symptoms and positivity 10 days after the first day of treatment. SARS-CoV-2 test was positive as on 23-May-2022. It was noted that patient received dose with Johnson and Johnson 6 months 26 days prior to current vaccination (Interchange of vaccine products). Ongoing Covid 19 pandemic could be considered as confounder to the event. The benefit-risk relationship of mRNA-1273 Vaccine is not affected by this report. Event seriousness assessed as per medical judgement.; Sender's Comments: This is a spontaneous case concerning a 46-years-old male patient with no relevant medical history, who experienced the unexpected non-serious adverse events of special interest, COVID-19 (COVID-19) which occurred 6 months 13 days after receiving a dose of mRNA-1273 vaccine (dose number not specified). The event COVID-19 was reported as; Rebound of COVID symptoms and positivity 10 days after the first day of treatment. SARS-CoV-2 test was positive as on 23-May-2022. It was noted that patient received dose with Johnson and Johnson 6 months 26 days prior to current vaccination (Interchange of vaccine products). Ongoing Covid 19 pandemic could be considered as confounder to the event. The benefit-risk relationship of mRNA-1273 Vaccine is not affected by this report. Event seriousness assessed as per medical judgement.