CONFIRMED CLINICAL VACCINATION FAILURE; CONFIRMED COVID-19 INFECTION; REVACCINATION WITH DIFFERENT COVID-19 VACCINE; This spontaneous report received from a patient through other manufacturer (Pfizer Inc.) concerned a 57 year old male. Initial information was processed along with the additional information received on 21-MAR-2023. The patient's height, and weight were not reported. The patient's concurrent conditions included: high blood pressure, and allergy, and other pre-existing medical conditions included: The patient had no history of past drug. The patient stated he was taking other medication or products within 2 weeks of starting covid-19 treatment (Paxlovid). The patient received covid-19 vaccine ad26.cov2.s (Dose number in series 1) (suspension for injection, route of admin not reported, batch number: Unknown, expiry: unknown) dose was not reported, single dose 1 total was administered on 06-APR-2021 to left arm for covid-19 prophylaxis. The batch number was not reported and has been requested. Age at time of vaccination 56 years old. No concomitant medications were reported. The patient received second dose of non-company suspect vaccine Moderna covid-19 vaccine (elasomeran) (Dose number in series 2) (form of admin, route of admin not reported, batch number: Unknown, expiry: unknown) dose was not reported, administered on 15-SEP-2021 to left arm for covid-19 prophylaxis.  It was unknown whether patient had any adverse events following vaccination with 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 admin, route of admin not reported, batch number: Unknown, expiry: unknown) dose was not reported, administered on 01-JUN-2022 to left arm for covid-19 prophylaxis. It was unknown whether patient had any adverse events following vaccination with Moderna covid-19 vaccine (elasomeran) (Dose number in series 3). The patient received fourth dose of non-company suspect vaccine Pfizer biontech covid-19 vaccine (tozinameran) (Dose number in series 4) (form of admin, route of admin not reported, batch number: Unknown, expiry: unknown) dose was not reported, administered on 01-NOV-2022 to left arm for covid-19 prophylaxis which was associated with revaccination with different covid-19 vaccine (Dose number in series 4). On 02-MAR-2023, the patient started to have symptoms for which on second day patient took non-company suspect drug Paxlovid (nirmatrelvir/ritonavir) (form of admin, route of admin not reported, batch number: Unknown, expiry: unknown) dose and frequency were not reported from 03-MAR-2023 to 08-MAR-2023 for treatment of covid-19. On an unspecified date patient had Laboratory data  included: COVID-19 virus test Positive (confirmed covid-19 infection) (Dose number in series 4) which resulted to confirmed clinical vaccination failure (Dose number in series 1). On 11-MAR-2023 (8 days after first dose of treatment with Paxlovid), he was tested positive for COVID-19 virus test, also patient was never tested negative for COVID-19 during or after the course of treatment with non-company suspect drug paxlovid. The action taken with covid-19 vaccine ad26.cov2.s, elasomeran, elasomeran, and tozinameran was not applicable; and action taken with nirmatrelvir/ritonavir was not reported. The patient had not recovered from confirmed covid-19 infection, and the outcome of confirmed clinical vaccination failure and revaccination with different covid-19 vaccine was not reported. This report was serious (Other Medically Important Condition). This report was associated with a product quality complaint: 90000275779.; Sender's Comments: V0: 20230351456- confirmed clinical vaccination failure. The event has a compatible/suggestive temporal relationship, is unlabeled, and has unknown scientific plausibility. There are other factors more likely to be associated with the event. Specifically: SPECIAL SITUATIONS. Therefore, this event is considered inconsistent with vaccine administration.