Inappropriate schedule of vaccine administered; I am having a rebound of COVID-19 and still testing positive. I initially had COVID symptoms on the evening of May 08.; This spontaneous case was reported by a patient and describes the occurrence of COVID-19 (I am having a rebound of COVID-19 and still testing positive. I initially had COVID symptoms on the evening of May 08.) and INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION (Inappropriate schedule of vaccine administered) 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.    Concurrent medical conditions included Sulfonamide allergy.   On 25-Jan-2021 at 2:00 PM, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 18-Mar-2021 at 12:00 PM, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 08-Aug-2021 at 2:00 PM, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 30-Apr-2022 at 4:00 PM, received fourth dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 10-May-2022, the patient started NIRMATRELVIR, RITONAVIR (PAXLOVID) (unknown route) at an unspecified dose. On 08-May-2022 at 8:00 AM, the patient experienced COVID-19 (I am having a rebound of COVID-19 and still testing positive. I initially had COVID symptoms on the evening of May 08.). On an unknown date, the patient experienced INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION (Inappropriate schedule of vaccine administered). The patient was treated with CHLORPHENAMINE MALEATE, PARACETAMOL (CORICIDIN HBP COLD AND FLU) on 21-May-2022 for COVID-19, at an unspecified dose and frequency. At the time of the report, COVID-19 (I am having a rebound of COVID-19 and still testing positive. I initially had COVID symptoms on the evening of May 08.) had not resolved and INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION (Inappropriate schedule of vaccine administered) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, SARS-CoV-2 test: positive (Positive) Positive.         No concomitant medication was provided by reporter.  Patient taking other medications/products within 2 weeks of starting COVID-19 treatment. The patient previously receive a COVID-19 Vaccine. Company comment: This is a spontaneous case concerning a 46-year-old male patient, with no relevant medical history, who experienced the unexpected, non-serious AESI of COVID-19 (reported as rebound of COVID-19), 8 days after the fourth dose of mRNA-1273 vaccine. Doses 1 and 2 were administered in an inappropriate schedule of vaccination (52-day interval). As per source document, he received Paxlovid and CHLORPHENAMINE MALEATE, PARACETAMOL as treatment and at the moment of report he still tested positive for SARS-CoV-2. The co-suspect PAXLOVID remains as a confounder for the event. The benefit-risk relationship of mRNA-1273 is not affected by this report.   This case was linked to MOD-2022-574872 (Patient Link).; Sender's Comments: This is a spontaneous case concerning a 46-year-old male patient, with no relevant medical history, who experienced the unexpected, non-serious AESI of COVID-19 (reported as rebound of COVID-19), 8 days after the fourth dose of mRNA-1273 vaccine. Doses 1 and 2 were administered in an inappropriate schedule of vaccination (52-day interval). As per source document, he received Paxlovid and CHLORPHENAMINE MALEATE, PARACETAMOL as treatment and at the moment of report he still tested positive for SARS-CoV-2. The co-suspect PAXLOVID remains as a confounder for the event. The benefit-risk relationship of mRNA-1273 is not affected by this report.