CONFIRMED CLINICAL VACCINATION FAILURE; CONFIRMED COVID-19 INFECTION; REVACCINATION WITH DIFFERENT COVID-19 VACCINE; This spontaneous report received from a patient via other company (Pfizer Inc.) concerned a 63 year old female. Initial information was processed along with the additional information received on 23-MAR-2023. The patient's height, and weight were not reported. The patient's concurrent conditions included: penicillin allergy, and other pre-existing medical conditions included: The patient was not pregnant at the time of vaccination. The patient received previously 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) 1 in total, dose, start therapy date were not reported, administered on left arm for covid-19 prophylaxis. Age at time of vaccination 7 decade old. The batch number was not reported and has been requested. No concomitant medications were reported. The patient additionally received 3 doses of Non-company suspect vaccine included: Pfizer BioNTech covid-19 vaccine (tozinameran) (dose number in series 2) (form of admin, route of admin, and batch number were not reported, expiry: unknown) dose was not reported, first dose administered on NOV-2021, second dose administered on DEC-2021 in left arm, third dose administered on JUL-2022 in left arm for covid-19 prophylaxis. It was unknown whether patient had any adverse events following vaccination with 3 doses of Pfizer BioNTech covid-19 vaccine (tozinameran) (dose number in series 2). The patient additionally received Non-company suspect vaccine included: Moderna covid-19 vaccine (elasomeran) (dose number in series 3) (form of admin, route of admin, and batch number were not reported, expiry: unknown) dose was not reported, administered on FEB-2023 in left arm for covid-19 prophylaxis which was associated with revaccination with different covid-19 vaccine (dose number in series 3).  On 03-MAR-2023 Friday, the patient became very ill, which was coded as confirmed covid-19 infection (dose number in series 3) that led to confirmed clinical vaccination failure (dose number in series 1).  The patient started taking treatment with Non-company suspect drugs included: nirmatrelvir/ritonavir (batch number: GF7861 expiry: UNKNOWN, form of admin, route of admin were not reported) dose and frequency were not reported from 04-MAR-2023 p.m to 09-MAR-2023 a.m for treatment of covid-19. The patient was not taking any other medications/products within 2 weeks of starting COVID-19 treatment. The patient tested negative on 11-MAR-2023 and again felt ill on 14-MAR-2023 p.m. and again tested positive for Covid-19 virus test in the a.m. on 15-MAR-2023, which was confirmed covid-19 infection (dose number in series 3). The action taken with covid-19 vaccine ad26.cov2.s, tozinameran, and elasomeran was not applicable; and action taken with nirmatrelvir/ritonavir was not reported. The outcome of the confirmed covid-19 infection, 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: 90000276146.; Sender's Comments: V0- 20230355784- 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.