Testing positive for Covid virus, after both vaccines/ after being fully vaccinated; Testing positive for Covid virus, after both vaccines/ after being fully vaccinated; This is a spontaneous report from a contactable consumer. This consumer reported for a 68-year-old male patient that.   A 68-years-old male patient received first dose of bnt162b2 (PFIZER-BIONTECH COVID-19 VACCINE, solution for injection, Batch/Lot Number: EJ1686), dose 1 via an unspecified route of administration on 16Jan2021 as single dose, second dose, via an unspecified route of administration on 06Feb2021 (Batch/Lot Number: EN5318) as single dose for COVID-19 immunisation. Medical history included myocardial infarction from Mar2021 to an unknown date. The patient concomitant medications were not reported. The patient experienced testing positive for covid virus, after both vaccines/ after being fully vaccinated on 23Mar2021. Reporter asking Question: Assistant Director of Health (non-HC) calling today from a withheld Health Department. She states they are monitoring and tracking the vaccine breakthrough cases in their area and she has some concerns regarding one specific lot number that 15% of their breakthrough cases had received. The lot number provided was EN5318. The caller at the time, did not have the NDC or expiration date, however, was going to work on pulling patient information so that she would be able to have this information available to provide upon transfer. Spoke with withheld nurse. Response: Call warm transferred successfully for further capture of data from the caller regarding breakthrough cases (AE) as well as with lot number involved that has been the cause for concern today. Upon Follow-up Agent states the Caller is an Assistant Director of Health and works at a local health department in withheld. Agent states the Caller called because she had some concerns, and the health department is tracking breakthrough cases in her area. Agent reports that Caller states 15% of breakthrough cases are from one Pfizer Covid 19 Lot number: EN5318. Agent confirms Caller is calling about the Pfizer Covid 19 vaccine. Successful warm transfer to DSU. Caller reclarifies later in report that 15% of the breakthrough cases in her county had the same lot number, EN5318, which was concerning. Caller states, reclarified later in report, she has 37 patients with partial identifiers. Caller states she cannot provide some identifying details and that she would need to check with her legal department first. Caller provides the details she is allowed to identify. Caller states 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 later states, she cannot provide the zip code. Later Caller states that Covid positive is defined as having both vaccines and testing positive for Covid longer than two weeks after both doses on 23Mar2021. Outcome of the events unknown at this time. Report 4 of 37, reports on a 68-year-old male. Partial identifiers provided by Caller. Full details not obtained. Caller is not allowed to provide some identifying details, at this time. One outbound call # made due to remote disconnection, on 19Aug2021, at 1:43 PM, and report continued. Description of complaint: Caller reporting on the Pfizer Covid 19 vaccine. Caller reports 37 breakthrough cases, for fully vaccinated patients testing positive for Covid. Some identifying details provided. Product strength and count size dispensed: not applicable. Additional lot numbers: not applicable Is a sample of the product available to be returned, if requested: No. Packaging sealed and intact was unknown. The patient underwent lab tests and procedures which included sars-cov-2 test: positive on 23Mar2021. The outcome of events was unknown.; Sender's Comments: Linked Report(s) : US-PFIZER INC-202101075254 Same reporter/drug/AE, different patients