This spontaneous case was reported by an other health care professional and describes the occurrence of COVID-19 (Tested negative on day 6, then Rebound with symptoms on day 10) in a 72-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 048F21A) for COVID-19 vaccination. Co-suspect product included non-company product NIRMATRELVIR, RITONAVIR (PAXLOVID) for COVID-19 treatment. Concurrent medical conditions included Chronic lymphocytic leukemia (in remission) and Sulfonamide allergy. On 09-Sep-2021, the patient received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 03-May-2022, the patient started NIRMATRELVIR, RITONAVIR (PAXLOVID) (unknown route) at an unspecified dose. On 12-May-2022, after starting mRNA-1273 (Moderna COVID-19 Vaccine), the patient experienced COVID-19 (Tested negative on day 6, then Rebound with symptoms on day 10). At the time of the report, COVID-19 (Tested negative on day 6, then Rebound with symptoms on day 10) had not resolved. DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 12-May-2022, SARS-CoV-2 test: positive (Positive) Positive. For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter did not provide any causality assessments. No concomitant medications were reported. Pfizer had permission to contact you about this report. Pfizer had permission to patient's healthcare provider about this report. The patient did not take any other medications/products within 2 weeks of starting COVID-19 treatment. Patient had previously received a COVID-19 Vaccine. Company Comment: This spontaneous case concerns a 72 year old female patient with relevant medical history of Chronic lymphocytic leukemia (in remission) with reported Co-suspect product included non-company product NIRMATRELVIR, RITONAVIR (PAXLOVID) for COVID-19 treatment, who experienced Non-serious, unexpected, AESI of COVID-19 which occurred 8 months, 3 days post vaccination with the third dose of mRNA-1273 vaccine. The information regarding the dose 1 and dose 2 of the COVID-19 vaccine of this patient was not reported. The SARS-Covid 2 test of this patient was positive dated 12-05-2022 and she was reported to have tested negative on day 6, then Rebound with symptoms on day 10. This patient took the Co-suspect drug Paxlovid from May 3-8 , 2022. Other treatment information, results of laboratories/diagnostic procedures were not reported and there was no report if any medical consult was done. Outcome of the event was reported as not resolved. The age of this patient, and her medical history of Chronic lymphocytic leukemia are considered as confounders for the event. The benefit -risk relationship of mRNA -1273 (Moderna COVID-19 Vaccine) is not affected by this report. Sender's Comments: This spontaneous case concerns a 72 year old female patient with relevant medical history of Chronic lymphocytic leukemia (in remission) with reported Co-suspect product included non-company product NIRMATRELVIR, RITONAVIR (PAXLOVID) for COVID-19 treatment, who experienced Non-serious, unexpected, AESI of COVID-19 which occurred 8 months, 3 days post vaccination with the third dose of mRNA-1273 vaccine. The information regarding the dose 1 and dose 2 of the COVID-19 vaccine of this patient was not reported. The SARS-Covid 2 test of this patient was positive dated 12-05-2022 and she was reported to have tested negative on day 6, then Rebound with symptoms on day 10. This patient took the Co-suspect drug Paxlovid from May 3-8, 2022. Other treatment information, results of laboratories/diagnostic procedures were not reported and there was no report if any medical consult was done. Outcome of the event was reported as not resolved. The age of this patient, and her medical history of Chronic lymphocytic leukemia are considered as confounders for the event. The benefit -risk relationship of mRNA -1273 ( Moderna COVID-19 Vaccine) is not affected by this report.