Predictors of Covid-19 Vaccination Response After In-Vivo T-Cell–Depleted Stem Cell Transplantation

COVID‐19 in hematopoietic stem‐cell transplant recipients: A systematic review and meta‐analysis of clinical characteristics and outcomes

“…38,39 Some studies have evaluated possible reasons for a worse immune response in HSCT recipients after vaccination. 38,40 Variables found to be associated to a suboptimal vaccine seroconversion in allogeneic-HSCT patients included lymphopenia, 40 the presence of chronic GVHD, 40 vaccination within the first year of transplantation, 40 and haploidentical transplantation. 38 HSCT patients with these characteristics might be mor prone for breakthrough infections.…”

COVID-19 and HSCT (Hematopoietic stem cell transplant)

“…A 2021 CIBMTR study suggested that cryopreservation during the COVID-19 pandemic was associated with slower engraftment of PBSC grafts, but no statistically significant effect on non-relapse mortality, progression-free survival or overall survival [ 10 ]. Encouragingly, there are early data to suggest the shift to cryopreserved products among other adaptations, allowed lifesaving transplant operations to continue [ 11 ]; and, over time, cryopreserved products were increasingly acceptable to transplant centers [ 12 ].…”

“…Admittedly, the screening protocols and management algorithms with regard to deferral timeline in the case of a positive test, in particular in a potential donor, are not “data driven.” While there is evidence of donor-derived COVID-19 transmitted by lung transplantation [ 15 , 16 ], there is to date no confirmed instance of transmission via cellular transplant [ 17 ]. In fact, there are several reports describing of use of stem cells harvested from donors who tested positive for SARS-CoV-2 by PCR on nasopharyngeal swab at the time of cell collection, without documented transmission to the recipients [ 12 , 18 , 19 ]. However, in the absence of data and while SARS-CoV-2 continues to circulate in the community, it will fraught to step back or pivot from donor and recipient screening protocols.…”

“…ǂ variable definition of severe disease, *variable follow-up time. Author, site(s) Diagnosis period # HSCT recipients: auto/allo/CAR-T Age, years – median (range) Time since HSCT or CAR-T – median (range) % asymptomatic % hospitalized % required supplemental O2 % required ICU care % require mechanical ventilation % severe COVID ǂ % COVID-specific mortality* % overall mortality* % mortality (by time from diagnosis) Altuntas, Republic of Turkey (Ministry of Health database) 3/11/20–5/29/20 32: 20/12/0 56.5 [ [17] , [18] , [19] ] 100 22 16 22 16 Coll, Spain (national)*not all lab confirmed on or before 7/13/20 113: 42/71/0 Auto:60 [ [55] , [56] , [57] , [58] , [59] , [60] , [61] , [62] , [63] , [64] ] 18 months [ [4] , [5] , [6] , [7] , [8] , [9] , [10] , [11] , [12] , [13] , [14] , [15] , [16] , [17] , [18] , [19] , [20] , [21] ...…”

“…Vaccine efficacy in HSCT recipients: While highly immunogenic in the populations included in the large-scale studies that led to vaccine licensing, at least against the original outbreak strain of SARS-CoV-2, numerous, mostly single-center immunogenicity studies have demonstrated decreased, but highly variable, in vitro immune response in HSCT recipients to a 2- or 3-dose mRNA vaccine series as measured by neutralizing antibody and/or T-cell response [ 12 , [62] , [63] , [64] , [65] , [66] , [67] , [68] , [69] , [70] , [71] ]. Not surprisingly, recency of HSCT, immunosuppressive therapy, lymphopenia, active malignancy and GVHD have all been demonstrated to be associated with dampened immune response.…”