both the CD4+ and CD8+ populations of ICOS+CD38+ T cells were deficient in a participant who later experienced a breakthrough SARS-CoV-2 infection between days 105-180; both the CD4+ and CD8+ populations of ICOS+CD38+ T cells were deficient in a participant who later experienced a breakthrough SARS-CoV-2 infection between days 105-180; This is a literature report for the following literature source(s):(withheld).   A patient (no qualifiers provided) received BNT162b2 (BNT162B2), as dose 1, single (Batch/Lot number: unknown) and as dose 2, single (Batch/Lot number: unknown) for covid-19 immunisation. The participant was received two doses of vaccine 21 days apart. The effect of BNT162b2 immunization was explored on recipient T-cell populations in a cohort of ten healthy participants with samples collected at Medical Center in late 2020 and early 2021 following early Alpha and Beta variants but prior to the onset of Delta and later variants. The patient's relevant medical history and concomitant medications were not reported. The following information was reported: VACCINATION FAILURE (medically significant), COVID-19 (medically significant), outcome "unknown" and all described as "both the CD4+ and CD8+ populations of ICOS+CD38+ T cells were deficient in a participant who later experienced a breakthrough SARS-CoV-2 infection between days 105-180". Findings: Responding lymphocyte populations correlate with eventual SARS-CoV-2 IgG, and a participant lacking these cell populations failed to sustain SARS-CoV-2-specific antibodies and experienced breakthrough infection. In this work, we employ unbiased approaches to identify and track the development of antigen-specific T and B cells in longitudinal samples from healthy participant recipients of the BNT162b2 RNA-based SARS-CoV-2 vaccine, including a participant with a subsequent breakthrough SARS-CoV-2 infection. We also identify expanding and metabolically active S protein specific, CD4+ and CD8+ T-cell populations following vaccination and confirm antigen specificity in vitro assays. In parallel, single-cell LIBRA-seq and RNA-seq of coronavirus S protein binding B cells establish the evolution of cross-reactive to antigen-specific B cells with public coronavirus antibody sequences over time. Antigen-specific T and B cells correlate and associate with a long-lasting IgG response and are not seen in a participant with subsequent breakthrough infection. These cell and antibody associations may drive further efforts to predict vaccine effectiveness and identify mechanisms of protection. The patient underwent the following laboratory tests and procedures: Blood immunoglobulin A: unknown results; Blood immunoglobulin G: unknown results; Blood immunoglobulin M: unknown results; CD4 lymphocytes: unknown results; CD8 lymphocytes: the participant with breakthrough SARS-CoV-2 infec, notes: tion failed to generate; Cell marker: unknown results; IL-2 receptor assay: were unaffected by the stimulation of T cells with, notes: S1 protein; Immunology test: unknown results; antigen-specific B-cell response: unknown results; unknown results; unknown results; unknown results; the participant with breakthrough SARS-CoV-2 infec, notes: tion failed to generate; showed a wide distribution; were unaffected by the stimulation of T cells with, notes: S1 protein; were unaffected by the stimulation of T cells with, notes: S1 protein; when incubated with S1 protein than samples stimul, notes: ated with activation beads; unknown results; unknown results; unknown results; unknown results; unknown results; Lymphoblast count: the participant with breakthrough SARS-CoV-2 infec, notes: tion failed to generate; SARS-CoV-2 antibody test: unknown results; Serology test: unknown results; unknown results.; Sender's Comments: Based on the information currently available, a lack of efficacy with bnt162b2 vaccine in this patient cannot be completely excluded