Tested positive for Covid virus, after being fully vaccinated; Tested positive for Covid virus, after being fully vaccinated; This is a spontaneous report from a contactable consumer. A 67-year-old male patient received BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE, Formulation: Solution for injection, Batch/Lot Number: EL9266) dose 2 via an unspecified route of administration on 23Feb2021 and the patient also received dose 1 BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE, Formulation: Solution for injection, Batch/Lot Number: EN5318 and Expiry date: 31May2021) via an unspecified route of administration on 28Jan2021  Single for covid-19 immunization administered in health district. Medical history included ongoing diabetes. The patient's concomitant medications were not reported. On 12Aug2021, the patient tested positive for covid virus, after being fully vaccinated and had vaccination failure. The patient underwent lab tests and procedures which included BMI (body mass index): 33.9, NAAT COVID test: positive on 12Aug2021. The Caller is an Assistant Director of Health and works at a local health department and called because she had some concerns, and the health department is tracking breakthrough cases in her area. She states 15% of breakthrough cases are from one Pfizer Covid 19 Lot number: EN5318. Caller reclarifies later in report that 15% of the breakthrough cases in her county had the same lot number, EN5318, which was concerning. And reclarified later in report, she has 37 patients with partial identifiers, and she cannot provide some identifying details and that she would need to check with her legal department first and she can provide, age, gender, BMI, medical conditions, if reported, and date they tested positive for Covid, and the type of Covid test utilized. Caller states that Covid positive is defined as having both vaccines and testing positive for Covid longer than two weeks after both doses. The outcome of event was unknown.  Conclusion of Previously Completed Investigation (FCI/SI/OffCI): The complaint for lack of effect of the PFIZER-BIONTECH COVID-19 VACCINE INJECTABLE lot EN5318 was investigated. The investigation included reviewing manufacturing and packaging batch records, deviation investigations, and an analysis of complaint history for the reported lot. The final scope was determined to be the reported finished goods lot EN5318, fill lot EN5317, and the formulated drug product lot EN5316. 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 were identified as the complaint was not confirmed. All release testing performed prior to the release of the reported batch was within specifications. When more than one investigation is found in the family, the Conclusion field could result in repeating rows for the CR in the table. If the Conclusion is blank in the table above, then the investigation record is likely an Offline Contractor Investigation and the conclusion must be obtained directly from the child investigation record(s) of the linked Complaint Record.  Follow-up attempts are completed. No further information is expected.; Sender's Comments: Linked Report(s) : US-PFIZER INC-202101076372 similar report from same reporter