COVID 19; COVID 19; This is a spontaneous report received from a contactable reporter(s) (Nurse) from product quality group. The reporter is the patient.  A 66-year-old female patient (not pregnant) received BNT162b2, BNT162b2 omi ba.4-5 (BNT162B2, BNT162B2 OMI BA.4-5), on 19Sep2022 as dose 4 (booster), single (Lot number: F59943) at the age of 65 years, in right arm for covid-19 immunisation; BNT162b2 (BNT162B2), on 09Feb2021 as dose 1, single (Lot number: EL9264), in right arm, on 03Mar2021 as dose 2, single (Lot number: EN6206) and on 11Oct2021 as dose 3 (booster), single (Lot number: FE3592), in right arm for covid-19 immunisation. The patient's relevant medical history included: "Chronic lymphocytic leukaemia" (unspecified if ongoing). The patient's concomitant medications were not reported. The following information was reported: VACCINATION FAILURE (medically significant), COVID-19 (medically significant), outcome "unknown" and all described as "COVID 19". Therapeutic measures were taken as a result of vaccination failure, covid-19.  Clinical course: Anti viral details: COVID 19 Treatment with Paxlovid from 11Apr2023 to 16Apr2023. Known allergies: NKA. Other medication in 2 weeks: Yes. Other medication details: other medication in 2weeks product=Norvasc, Levothyrozine and Elavil.  Conclusion of Previously Completed Investigation (FCI/SI/OffCI): The complaint for lack of effect of the PFIZER BIONTECH COVID-19 VACCINE lot EL9264 was investigated. The investigation included a review of manufacturing and packaging batch records, deviation investigations, and an analysis of complaint history for the reported lot and product type. The final scope included the reported finished goods lot EL9264, fill lot EL9255, and the formulated drug product lot EL9246. The final scope was determined to be the reported finished goods lot FE3592, fill lot FF2553, and the bulk formulated drug product lot FA9141. A complaint sample was not returned. No related quality issues were identified during the investigation. There is no impact on product quality. No root cause or CAPA were identified as the complaint was not confirmed. All release testing performed prior to the release of the reported batch was within specifications.  Conclusion of Previously Completed Investigation (FCI/SI/OffCI): The complaint for Lack of Effect with the product for the COVID-19 Vaccine was investigated. The investigation included review of manufacturing records, analytical results at the time of lot release, retained reference samples, deviations, and complaint lot history trends. The final scope was limited to include the reported finished goods lot EN6206, fill lot EN5339, the bulk formulated drug product lot EN5327. No returned complaint sample was received. All deviation investigations performed during the manufacturing process of the lot were reviewed. The conclusion of all investigations confirmed there was no quality issue which would affect the quality of the lot. No root cause or CAPA were identified as the complaint was not confirmed.; Sender's Comments: Based on the available information in the case, an association between the reported events VACCINATION FAILURE ,COVID-19  and The suspected drug cannot be ruled out.