Bitter, alkaline, soapy distaste in mouth during course of medication/Rebound infection with mild symptoms (runny nose and congestion, altered taste, brain fog, & fatigue); lack of drug effect; This spontaneous case was reported by a consumer and describes the occurrence of COVID-19 (Bitter, alkaline, soapy distaste in mouth during course of medication/Rebound infection with mild symptoms (runny nose and congestion, altered taste, brain fog, & fatigue)) and DRUG INEFFECTIVE (lack of drug effect) in a 30-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 062E21A, 026b21a and 036a21a) for COVID-19 vaccination.    Co-suspect product included non-company product NIRMATRELVIR, RITONAVIR (PAXLOVID) for COVID-19 treatment.    The patient's past medical history included ADHD, Ectopic heartbeats and Palpitations. Concurrent medical conditions included Migraine and Allergy (Allergy was reported to unknown past drug). Concomitant products included FLUTICASONE PROPIONATE (FLONASE [FLUTICASONE PROPIONATE]) from 07-Mar-2022 to 02-May-2022, AMFETAMINE SULFATE (AMPHETAMINE SALTS) from 07-Feb-2022 to 01-May-2022 and AZELASTINE HCL from 06-Mar-2022 to 01-May-2022 for an unknown indication.   On 07-Mar-2021 at 1:00 AM, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 04-Apr-2021 at 11:00 AM, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 15-Oct-2021 at 4:00 AM, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 04-May-2022, the patient started NIRMATRELVIR, RITONAVIR (PAXLOVID) (unknown route) at an unspecified dose. In May 2022, the patient experienced COVID-19 (Bitter, alkaline, soapy distaste in mouth during course of medication/Rebound infection with mild symptoms (runny nose and congestion, altered taste, brain fog, & fatigue)) and DRUG INEFFECTIVE (lack of drug effect). At the time of the report, COVID-19 (Bitter, alkaline, soapy distaste in mouth during course of medication/Rebound infection with mild symptoms (runny nose and congestion, altered taste, brain fog, & fatigue)) was resolving and DRUG INEFFECTIVE (lack of drug effect) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, SARS-CoV-2 test: negative (Negative) Testing negative on antigen rapid at-home tests.         Bitter, alkaline, soapy distaste in mouth during course of medication that would start 1 hour after taking a and end up to 6 hours after. Used gum or food to mask the taste. Patient experienced rebound infection with mild symptoms (runny nose & congestion, altered taste, brain fog, & fatigue) starting 13 May, approx 5 days after finishing Paxlovid course and reporting no symptoms and testing negative on antigen rapid at-home tests. Still experiencing mild symptoms at this time.  Device Date : 15May2022  Company Comment: This spontaneous case concerns a 30-year-old male patient with no relevant medical history who experienced the unexpected non-serious AESI of COVID-19 which unspecified days (reported as in May 2021) after the second dose mRNA-1273 vaccine. Additionally, Vaccination failure is also reported as time interval between the two doses is 28 days.  Patient was administered with NIRMATRELVIR, RITONAVIR (Paxlovid) for 5 days as treatment for COVID-19 and was tested negative after 5 days and he experienced rebound infection with mild symptoms. He was tested positive for COVID-19. COVID-19 pandemic could be confounding for the event. The benefit-risk relationship of mRNA-1273 is not affected by this report.; Sender's Comments: This spontaneous case concerns a 30-year-old male patient with no relevant medical history who experienced the unexpected non-serious AESI of COVID-19 which unspecified days (reported as in May 2021) after the second dose mRNA-1273 vaccine. Additionally, Vaccination failure is also reported as time interval between the two doses is 28 days.  Patient was administered with NIRMATRELVIR, RITONAVIR (Paxlovid) for 5 days as treatment for COVID-19 and was tested negative after 5 days and he experienced rebound infection with mild symptoms. He was tested positive for COVID-19. COVID-19 pandemic could be confounding for the event. The benefit-risk relationship of mRNA-1273 is not affected by this report.