Symptoms of Rebound of COVID on day 5 after completing Plaxlovid, tested positive on day 6; Felt poorly the day before testing; Felt ill after each vaccination for 2 days; This spontaneous case was reported by a patient and describes the occurrence of COVID-19 (Symptoms of Rebound of COVID on day 5 after completing Plaxlovid, tested positive on day 6), MALAISE (Felt ill after each vaccination for 2 days) and FEELING ABNORMAL (Felt poorly the day before testing) in a 68-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 030L20A, 010A21A and 033F21A) for COVID-19 prophylaxis.    Co-suspect product included non-company product TOZINAMERAN (PFIZER BIONTECH COVID-19 VACCINE) for an unknown indication.    Concurrent medical conditions included Blood pressure high, Graves' disease, Hypothyroidism (Surgical Hypothyroidism), Osteoporosis and Drug allergy (Drug name unspecified). Concomitant products included LEVOTHYROXINE SODIUM (SYNTHROID) from February 2015 to an unknown date, AMLODIPINE from January 2011 to an unknown date, ESCITALOPRAM from May 2022 to an unknown date and LIOTHYRONINE from February 2017 to an unknown date for an unknown indication.   On 28-Jan-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 25-Feb-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On 04-Nov-2021, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On 15-Sep-2022, the patient received fourth dose of TOZINAMERAN (PFIZER BIONTECH COVID-19 VACCINE) (Intramuscular) 1 dosage form. On 01-Feb-2023, the patient experienced FEELING ABNORMAL (Felt poorly the day before testing). On 11-Feb-2023, the patient experienced COVID-19 (Symptoms of Rebound of COVID on day 5 after completing Plaxlovid, tested positive on day 6). On an unknown date, the patient experienced MALAISE (Felt ill after each vaccination for 2 days). The patient was treated with NIRMATRELVIR, RITONAVIR (PAXLOVID) (oral) from 01-Feb-2023 to 06-Feb-2023 for COVID-19, at an unspecified dose and frequency. In February 2023, FEELING ABNORMAL (Felt poorly the day before testing) had resolved. At the time of the report, COVID-19 (Symptoms of Rebound of COVID on day 5 after completing Plaxlovid, tested positive on day 6) was resolving and MALAISE (Felt ill after each vaccination for 2 days) had resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 01-Feb-2023, SARS-CoV-2 test: Positive. On 06-Feb-2023, SARS-CoV-2 test: Positive. On 12-Feb-2023, SARS-CoV-2 test: Positive.         Concomitant medication of the patient was also included Raloxifene.  After Paxlovid the patient felt better. The patient isolated her for 5 days. Tested positive again on day 6 and reisolated.   Most recent FOLLOW-UP information incorporated above includes: On 16-Mar-2023: Upon significant follow-up; case classification, reporter information and suspect product information were updated. Additional events, patient details (height, weight and age at vaccination) and lab test were added. Event description was updated accordingly. On 16-Mar-2023: Follow up document received contains no significant information.