key: cord-0936725-2epbej8i authors: Agrati, Chiara; Castilletti, Concetta; Sacchi, Alessandra; Colavita, Francesca; Capobianchi, Maria Rosaria; Puro, Vincenzo; Nicastri, Emanuele; Ippolito, Giuseppe; Bibas, Michele title: Immunogenicity and safety of BNT162b2 COVID‐19 vaccine in a chronic lymphocytic leukaemia patient date: 2021-05-25 journal: J Cell Mol Med DOI: 10.1111/jcmm.16565 sha: d05af0fa7751fdc53557102b55c9a22633c61e2b doc_id: 936725 cord_uid: 2epbej8i nan To the editor, Up to date, more than 310 million doses of coronavirus vaccines have been administered around the world. Despite these large numbers, there are no data describing the immunogenicity and safety of commercially available vaccines against SARS-CoV-2 in patients with haematologic malignancies. In particular, no clinical trials of a coronavirus disease-19 (COVID-19) vaccine have enrolled patients with chronic lymphocytic leukaemia (CLL), and there is not even a single report describing the capability of CLL patients to generate humoral and cellular response against COVID-19 after vaccination. This is very important being CLL the most common type of leukaemia in developed countries, with an age-adjusted incidence of 4-5 per 100.00 population. More, CLL represents the paradigm of neoplastic disease with immunodeficiency and increased susceptibility to infections is seen from the time of diagnosis, related to quantitative and qualitative defects within the innate and adaptive immune response. 1 Infections are the major cause of death in 30%-50% of persons with CLL, so patients with CLL are supposed to be at high-risk COVID-19. Recently, two multicentre studies have reported a high morbidity and mortality rate in CLL patients with COVID-19, both in treated and in 'watch and wait' group. 2, 3 Further, the development of a serologic response after SARS-CoV-2 infection is compromised in CLL, as one study reported that nearly only one-third of patients develop detectable immunoglobulin G (IgG) antibodies after a median of 2 months after infection. 4 Based on the documented lower immune response to other vaccines, 5, 6 there are theoretical concerns about the capability of CLL patients to generate a fully protective immune response to SARS- We wanted then to answer the question if a CLL patient could mimic the robust immune response to the BNT162b2 vaccine seen in the immunocompetent population. Here, we describe, to our knowledge, the first report of the Corrente, COVID-2020-12371817, COVID-2020-12371735) Spallanzani COVID-19 Case Investigation Team: Casetti R., Notari S., Lapa D., Meschi S. The authors declare no competing financial interests. The frequency of T cells was low but CD4/CD8 T cell ratio was in the normal range. B,C, A significant increase in anti-RBD IgG and in the neutralization titres was observed 2 weeks after boost (T2), although at lower level than HCWs. VNT (viral neutralization titre).D, Spikespecific T cell response was detected before the boost (T1) and strongly increased at T2, reaching level similar to HCW. Data from HCWs (n = 10) are shown as boxer and whiskers plot (median, 25th and 75th percentile) Chronic lymphocytic leukaemia Outcomes of COVID-19 in patients with CLL: a multicenter international experience COVID-19 severity and mortality in patients with chronic lymphocytic leukemia: a joint study by ERIC, the European Research Initiative on CLL, and CLL Campus Anti-SARS-CoV-2 antibody response in patients with chronic lymphocytic leukemia Response to the conjugate pneumococcal vaccine (PCV13) in patients with chronic lymphocytic leukemia (CLL) The humoral immune response to high-dose influenza vaccine in persons with monoclonal B-cell lymphocytosis (MBL) and chronic lymphocytic leukemia (CLL) Safety and efficacy of the BNT162b2 mRNA Covid-19 vaccine https://orcid.org/0000-0001-5689-7759