Treatment of COVID-19; Treatment of COVID-19; This is a spontaneous report received from contactable reporter(s) (Consumer or other non HCP) from product quality group. The reporter is the patient.  A 79-year-old female patient (not pregnant) received BNT162b2 (PFIZER-BIONTECH MRNA COVID-19 VACCINE), on 27Jan2021 at 13:00 as dose 1, single (Lot number: EL8982), in left arm, on 17Feb2021 at 13:00 as dose 2, single (Lot number: EM9809), in left arm, on 16Aug2021 at 13:00 as dose 3 (booster), single (Lot number: EW0182), in left arm and on 28Jan2022 at 12:00 as dose 4 (booster), single (Lot number: FK9729) at the age of 78 years for covid-19 immunisation. The patient's relevant medical history included: "chronic ITP" (unspecified if ongoing). Concomitant medication(s) included: CELLCEPT [MYCOPHENOLATE MOFETIL]; PROMACTA; LISINOPRIL; SIMVASTATIN; VITAMIN D3; VITAMIN C [ASCORBIC ACID]; ESTRADIOL; PRESERVISION AREDS 2; CELECOXIB; ESCITALOPRAM. The following information was reported: VACCINATION FAILURE (medically significant), COVID-19 (medically significant), outcome "unknown" and all described as "Treatment of COVID-19". The patient underwent the following laboratory tests and procedures: SARS-CoV-2 test: Unknown results, notes: COVID 19 Treatment. Therapeutic measures were taken as a result of vaccination failure, covid-19.  Based on product investigation results, the complaint for lack of effect of the PFIZERBIONTECH COVID-19 VACCINE lot EL8982 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. The final scope included the reported finished goods lot EL8982, fill lot EL8977, and the formulated drug product lot EL8975. 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.  Based on product investigation results, the complaint for lack of effect of the PFIZERBIONTECH COVID-19 VACCINE lot EW0182 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. The final scope included the reported finished goods lot EW0182, fill lot EP8733, and the formulated drug product lot EP8614. A complaint sample was not returned. No related quality issues were identified during the investigation. There is no impact to product quality. No root cause or corrective/preventative actions were identified as the complaint was not confirmed. All release testing performed prior to the release of the reported batch was within specifications.  Based on product investigation results, the complaint for lack of effect of the PFIZERBIONTECH COVID-19 VACCINE lot EM9809 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. The final scope included the reported finished goods lot EM9809, fill lot EM9807, and the formulated drug product lot EM9805. A complaint sample was not returned, and photographs were not received. No related quality issues were identified during the investigation. There is no impact to product quality. No root cause or corrective/preventative actions were identified as the complaint was not confirmed. All release testing performed prior to the release of the reported batch was within specifications.  Based on product investigation results, for this lot Adverse Event Safety Request For Investigation and/or Lack Of Effect was previously investigated. All analytical results were checked and were within registered limits. The investigation of the referenced resulted in the following conclusion: Reference (see File attachment in this investigation record) The complaint for "PFIZERBIONTECH COVID-19 VACCINE was investigated. The investigation included reviewing the involved batch records, deviation investigation, an analysis of the complaint history for the reported lot and product type. The final scope was determined to be the associated lot(s) of the reported lot FK9729. A complaint sample was not returned. No related quality issues were identified during the investigation. There is no impact on product quality, regulatory, validation and stability. Agency concludes that the reported defect is not representative of the quality of the batch and the batch remains acceptable. The process determined that no regulatory notification was required. The reported defect could not be confirmed. No root cause or CAPA were identified as the complaint was not confirmed.