COVID-19; Experienced rebound symptoms positive antigen test 4 days after completing Paxlovid treatment; This spontaneous case was reported by a consumer and describes the occurrence of COVID-19 (Experienced rebound symptoms positive antigen test 4 days after completing Paxlovid treatment) and COVID-19 (COVID-19) in a 38-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 066F21A) for COVID-19 vaccination.     Concurrent medical conditions included Allergy NOS (unknown historical drug).    On 12-Nov-2021, the patient received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 12-May-2022, the patient experienced COVID-19 (Experienced rebound symptoms positive antigen test 4 days after completing Paxlovid treatment). On an unknown date, the patient experienced COVID-19 (COVID-19). The patient was treated with NIRMATRELVIR, RITONAVIR (PAXLOVID) from 03-May-2022 to 08-May-2022 for COVID-19 treatment, at an unspecified dose and frequency. At the time of the report, COVID-19 (Experienced rebound symptoms positive antigen test 4 days after completing Paxlovid treatment) and COVID-19 (COVID-19) had not resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 05-May-2022, SARS-CoV-2 test: negative (Negative) Tested antigen negative 2 days after beginning Paxlovid treatment.. On 12-May-2022, SARS-CoV-2 test: positive (Positive) Positive. On an unknown date, SARS-CoV-2 test: positive (Positive) Positive.         No concomitant medications was provided by the reporter. No treatment medications was provided by the reporter.  the patient did not take any other medications/products within 2 weeks of starting COVID-19 treatment and the patient previously received a COVID-19 Vaccine. Device Date: 14 May 2022  Company comment: This spontaneous case concerns a 38 year old male patient with no reported medical history who experienced the unexpected, non-serious adverse event of special interest of COVID-19 (reported twice- 1. LLT of COVID-19 and 2. LLT of COVID-19 Recurrent). The event COVID-19 (LLT COVID-19) occurred at an unspecified date after receiving a dose of mRNA1273 as third dose of COVID-19 vaccine, the second event of COVID-19 (LLT COVID-19 recurrent) occurred 6 months post vaccination. The patient tested positive on the COVID-19 antigen test (at an unknown date) and was treated with Nirmatrelvir and Ritonavir (Paxlovid) for 5 days at an unspecified dose and frequency. He experienced rebound symptoms and tested positive for COVID-19 antigen 4 days after completing Paxlovid treatment. The patient did not take any other medications or products within 2 weeks of starting COVID-19 treatment. The events are not yet resolved at the time of this report. The benefit-risk relationship of mRNA-1273 is not affected by this report.; Sender's Comments: This spontaneous case concerns a 38 year old male patient with no reported medical history who experienced the unexpected, non-serious adverse event of special interest of COVID-19 (reported twice- 1. LLT of COVID-19 and 2. LLT of COVID-19 Recurrent). The event COVID-19 (LLT COVID-19) occurred at an unspecified date after receiving a dose of mRNA1273 as third dose of COVID-19 vaccine, the second event of COVID-19 (LLT COVID-19 recurrent) occurred 6 months post vaccination. The patient tested positive on the COVID-19 antigen test (at an unknown date) and was treated with Nirmatrelvir and Ritonavir (Paxlovid) for 5 days at an unspecified dose and frequency. He experienced rebound symptoms and tested positive for COVID-19 antigen 4 days after completing Paxlovid treatment. The patient did not take any other medications or products within 2 weeks of starting COVID-19 treatment. The events are not yet resolved at the time of this report. The benefit-risk relationship of mRNA-1273 is not affected by this report.