SUSPECTED CLINICAL VACCINATION FAILURE; SUSPECTED COVID-19 INFECTION; EXTREMELY BITTER TASTE; This spontaneous report received from a consumer via other manufacturer (Pfizer) concerned a patient of an unspecified age, sex, race and ethnicity. The patient's height, and weight were not reported. The patient's concurrent conditions included: type 1 diabetes, hypothyroidism, and drug allergy with dicloxacillin, pfenergan, inapsine and reglan. The patient received first dose of covid-19 vaccine ad26.cov2.s (dose number in series 1) (suspension for injection, route of administration, batch number were not reported, expiry: unknown) dose was not reported, 1 in total was administered on 03-APR-2021 for prophylactic vaccination. The batch number was not reported. The Company is unable to perform follow-up to request batch/lot numbers. The patient received second dose of non-company suspect vaccine Moderna Covid-19 vaccine (elasomeran) (dose number in series 2) (form of administration, route of administration, batch number were not reported, expiry: unknown), dose was not reported, administered on 04-OCT-2021 to right arm for prophylactic vaccination. It was unknown whether patient had any adverse events following vaccination with second dose of Moderna Covid-19 vaccine (elasomeran) (dose number in series 2). The patient received third dose of non-company suspect vaccine Moderna Covid-19 vaccine (elasomeran) (dose number in series 3) (form of administration, route of administration, batch number were not reported, expiry: unknown), dose was not reported, administered on 03-APR-2022 to left arm for prophylactic vaccination. Concomitant medications included gabapentin, insulin, levothyroxine, and metoprolol. On an unspecified date, the patient experienced suspected covid-19 infection (dose number in series 3) and suspected clinical vaccination failure (dose number in series 1).  On 18-JUN-2022, the patient was treated with non-company suspect drug Paxlovid (form of admin, route of administration, batch number and expiry were not reported) dose and frequency were not reported administered for the treatment of covid-19 and was last administered on 22-JUN-2022. On 18-JUN-2022, the patient experienced extremely bitter taste in the mouth which lasted for greater than 12 hours. It came and went and brushing teeth nor mouthwash did nothing. It subsided if the patient ate something, but the bitter taste started again and tasted like chewing on a mouthful of vitamins or bitter medications (dose number in series 3). The action taken with covid-19 vaccine ad26.cov2.s and elasomeran was not applicable. The patient recovered from extremely bitter taste, and the outcome of suspected clinical vaccination failure and suspected covid-19 infection was not reported. This report was serious (Other Medically Important Condition). This report was associated with a product quality complaint, and reference number requested.; Sender's Comments: V0. 20220706806-covid-19 vaccine ad26.cov2.s -Suspected clinical vaccination failure. The event(s) has an unknown/unclear temporal relationship, is unlabeled, and has unknown scientific plausibility. There are other factors more likely to be associated with the event(s) than the drug. Specifically: SPECIAL SITUATIONS. Therefore, this event(s) is considered not related.