CONFIRMED CLINICAL VACCINATION FAILURE; CONFIRMED COVID-19 INFECTION; REVACCINATION WITH DIFFERENT COVID-19 VACCINE; This spontaneous report received from a health professional via other manufacturer (Pfizer) concerned a 66 year old male. The patient's height, and weight were not reported. The patient's pre-existing medical conditions included: The patient was physically active and in good health and did not took any oral medications. The patient had no known allergies. The patient received first dose of covid-19 vaccine ad26.cov2.s (Dose number in series 1) (suspension for injection, route of admin not reported, batch number: 1805022, expiry: UNKNOWN) dose was not reported, 1 total, administered on 09-MAR-2021 for covid-19 prophylaxis. Age at time of vaccination 64 years old. Concomitant medications included clobetasol propionate Occasional for drug used for unknown indication. The patient also received two doses of spikevax (moderna) (elasomeran) (Dose number in series 2) (form of admin and route of admin was not reported, batch number : 014F21A (second dose) and 056A22A (third dose) expiry: unknown) dose was not reported, administered second dose on 25-OCT-2021 and third dose on 26-APR-2022 for covid-19 prophylaxis. It was unknown whether the patient experienced any adverse events following vaccination with two doses of spikevax (moderna) (elasomeran) (Dose number in series 2). The patient also received fourth dose of pfizer biontech covid-19 vaccine (tozinameran) (Dose number in series 3) (form of admin and route of admin was not reported, batch number: E49702, expiry: Unknown) dose was not reported, administered at left arm on 09-OCT-2022 for covid-19 prophylaxis which was revaccination with different covid-19 vaccine (Dose number in series 3). On 17-OCT-2022, the patient tested covid-19 positive (confirmed COVID-19 infection) (Dose number in series 3) which resulted to Confirmed clinical vaccination failure (Dose number in series 1). On 22-OCT-2022, Laboratory data included: COVID-19 virus test Positive, hence patient received paxlovid (form of admin and route of admin was not reported, batch number: GG2065. SN756, expiry: MAY-2023) dose was not reported, administered from 24-OCT-2022 to 28-OCT-2022 for the treatment for covid-19. On 26-OCT-2022, Laboratory data included: COVID-19 virus test Positive. On 01-NOV-2022, Laboratory data included: COVID-19 virus test Negative. On 05-NOV-2022, Laboratory data included: COVID-19 virus test Positive again. The action taken with covid-19 vaccine ad26.cov2.s, elasomeran, and tozinameran was not applicable and with paxlovid was drug withdrawn. The patient was recovering from confirmed covid-19 infection, and the outcome of revaccination with different covid-19 vaccine and confirmed clinical vaccination failure was not reported. This report was serious (Other Medically Important Condition). This report was associated with a product quality complaint.; Sender's Comments: V0: 20221129141-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.