SUSPECTED CLINICAL VACCINATION FAILURE; SUSPECTED COVID-19 INFECTION; This spontaneous report received from a patient via other manufacturer Pfizer concerned a patient of unspecified age, sex, race and ethnic origin. Initial information was processed along with additional information received on 20-JUN-2022. The patient's height, and weight were not reported. The patient's concurrent conditions included: breast cancer, heart arrhythmia, and allergy. The patient received covid-19 vaccine ad26.cov2.s (Dose number in series 1) (suspension for injection, route of admin not reported, batch number: 041A21A expiry: unknown) dose was not reported, 01 total, administered on 09-APR-2021 for prophylactic vaccination. No concomitant medications were reported. On an unspecified date in MAY-2022, patient experienced Covid-19 symptoms which led to suspected clinical vaccination failure (Dose number in series 1). The patient received additional dose of non-company suspect vaccine Moderna COVID-19 vaccine (elasomeran) (Dose number in series 2) (form of administration and route of administration were not reported, batch number: 012H21B, expiry: unknown) dose was not reported, administered on 05-DEC-2021 for prophylactic vaccination. No concomitant medications were reported. On an unspecified date in MAY-2022 patient started experiencing Covid-19 symptoms (suspected Covid-19 infection) (Dose number in series 2) and received non company suspect paxlovid (form of administration and route of administration were not reported and batch number: unknown, expiry: unknown) dose was not reported, administered from 18-MAY-2022 till 22-MAY-2022 for covid-19 treatment. Patient symptoms improved after patient took paxlovid but on unspecified date in 2022 (Day 10), the patient had very faint positive Covid-19 test at home with no symptoms. On an unspecified date in 2022 (Day 11) started Covid-19 symptoms (headache, sore throat, aches and pains with cough and wheezing) (Dose number in series 2). On same day patient had very strong positive home Covid-19 test again . On 05-JUN-2022, the patient received steroids (Intravenous, oral and inhaler) for covid-19 infection. The action taken with covid-19 vaccine ad26.cov2.s and elasomeran was not applicable and paxlovid was drug discontinued . The patient had not recovered from suspected covid-19 infection, and the outcome of suspected clinical vaccination failure was not reported. This report was serious (Other Medically Important Condition). This report was associated with product quality complaint: 90000236418.; Sender's Comments: V0: 20220629758-Covid-19 vaccine ad26.cov2.s -Suspected Clinical Vaccination Failure. The event(s) 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(s) than the drug. Specifically: SPECIAL SITUATIONS. Therefore, this event(s) is considered not related. 20220629758 -Covid-19 vaccine ad26.cov2.s -Suspected Covid-19 infection. The event(s) has a compatible/suggestive temporal relationship, is unlabeled, and has unknown scientific plausibility. There is no information on any other factors potentially associated with the event(s). Therefore, this event(s) is considered unassessable.