Rebound effect/Have been testing positive/once again got a sore throat and a stuffed nose; the patient received first dose of Johnson & Johnson; This spontaneous case was reported by a patient and describes the occurrence of COVID-19 (Rebound effect/Have been testing positive/once again got a sore throat and a stuffed nose) and INTERCHANGE OF VACCINE PRODUCTS (the patient received first dose of Johnson & Johnson) in a 47-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination.     The patient's past medical history included Malignant melanoma (35 years ago). Previously administered products included for Product used for unknown indication: JANSSEN COVID-19 VACCINE (dose number 1 and right arm) in April 2021. Past adverse reactions to the above products included No adverse event with JANSSEN COVID-19 VACCINE. Concurrent medical conditions included Blood pressure high. Concomitant products included FINASTERIDE, LISINOPRIL from February 2021 to an unknown date and DOXYCYCLINE from 26-May-2022 to an unknown date for an unknown indication.    In November 2021, the patient received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. In November 2021, the patient experienced INTERCHANGE OF VACCINE PRODUCTS (the patient received first dose of Johnson & Johnson). On 29-May-2022, the patient experienced COVID-19 (Rebound effect/Have been testing positive/once again got a sore throat and a stuffed nose). The patient was treated with NIRMATRELVIR, RITONAVIR (PAXLOVID) from 29-May-2022 to 02-Jun-2022 for COVID-19 treatment, at an unspecified dose and frequency. At the time of the report, COVID-19 (Rebound effect/Have been testing positive/once again got a sore throat and a stuffed nose) was resolving and INTERCHANGE OF VACCINE PRODUCTS (the patient received first dose of Johnson & Johnson) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): In May 2022, SARS-CoV-2 test: positive (Positive) Have been testing positive again starting on day 8 to day 12. On 29-May-2022, SARS-CoV-2 test: positive (Positive) Initial positive test. On an unknown date, SARS-CoV-2 test: negative (Negative) Negative.         Patient do not have any allergy. Patient was taking medications within 2 weeks of starting COVID-19 treatment. It was reported that after patient tested negative, once again patient got a sore throat and a stuffed nose on 30-MAY-2022 and then tested positive again starting on day 8 after initial positive test and still positive on day 12 and started paxlovid within hours of initial positive test. Device date was given as 02-JUN-2022.  Company comment: This is a spontaneous case concerning a 47-year-old, male patient with no relevant medical history and with vaccine history of receiving first dose of Johnson & Johnson, who experienced the unexpected non-serious AESI event of Covid-19. The event occurred approximately 5-6 months after the second dose of mRNA-1273 vaccine administration, in Covid-19 vaccination in series. The event was described as, patient was tested positive and hours later received treatment with Nirmatrelvir + Ritonavir (Paxlovid) for Covid-19. Patient was tested negative. However, patient once again got sore throat and stuffed nose. Patient tested positive again. No other information surrounding the event was reported. The outcome of the event was reported as resolving. The current Covid-19 pandemic remain confounder for the event Covid-19. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.; Sender's Comments: This is a spontaneous case concerning a 47-year-old, male patient with no relevant medical history and with vaccine history of receiving first dose of Johnson & Johnson, who experienced the unexpected non-serious AESI event of Covid-19. The event occurred approximately 5-6 months after the second dose of mRNA-1273 vaccine administration, in Covid-19 vaccination in series. The event was described as, patient was tested positive and hours later received treatment with Nirmatrelvir + Ritonavir (Paxlovid) for Covid-19. Patient was tested negative. However, patient once again got sore throat and stuffed nose. Patient tested positive again. No other information surrounding the event was reported. The outcome of the event was reported as resolving. The current Covid-19 pandemic remain confounder for the event Covid-19. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.