Assessment of Serology after Sars-Cov-2 Vaccine in Allogeneic HCT Recipients

• Published in: Blood 2021-11, Vol.138 (Supplement 1), p.2900-2900
• Main Authors: Baker, Melissa, Cortes, Maria, Ahn, Jaeil, Donato, Michele L., Kaur, Sukhdeep, Suh, Hyung C., Morawski, Alison, McKiernan, Phyllis, Einstein, Amy, Boonstra, Michele, Rowley, Scott D.
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2021-145642

Introduction: Randomized trials demonstrated ~95% efficacy of SARS-CoV-2 spike messenger RNA (mRNA) vaccines. Patients (pts) after allogeneic hematopoietic cell transplant (HCT) have a variable period of immune deficiency and the impact of diagnosis, treatment regimens, GvHD, and immunosuppression on vaccine (vacc) immunogenicity is unknown. Methods: We performed a retrospective analysis of 149 consecutive pts (Table) who received a SARS-CoV-2 vacc between 12/17/2020, and 5/21/21, and were tested for anti-SARS-CoV-2 S1/S2 antibodies. Serology testing was performed with the Liaison® SARS-CoV-2 S1/S2 IgG assay (DiaSorin) with ≥15 AU/mL defined as a positive result. Pts with prior COVID-19 infection were excluded. Pts received mRNA-1273/Moderna (n= 46), BNT162b2/Pfizer-BioNTech (n= 100) or Jannsen vacc (n= 3). Reactogenicity was not investigated. Demographic and treatment variables were tested for prediction of vaccine response using Chi-square test or Fisher's exact test for categorical variables and two-sample t test for continuous variables. Univariate and multivariable logistic regression analyses with backward selection using Akaike information criterion (AIC) were used to examine interdependence of those variables and odds ratios (OR) with 95% confidence intervals (CI). Results: Pts underwent HCT from a related HLA matched sibling (n=36), related haploidentical (n= 23), or matched/mismatched unrelated donor (n= 89). 93% received fludarabine in the HCT conditioning regimen (data not shown). All pts received a calcineurin inhibitor (CNI) and 76 pts received ATG for GvHD prophylaxis. All pts achieved at least mixed donor lymphoid engraftment (data not shown). Median time from HCT to 1st vaccination was 26 months (range, 3-258 months). Median age at time of vaccination was 61 years (range, 24-78) and 75 (50%) were female. Serology was tested at a median of 37 days (range, 6-119 days) after the second vacc dose. Serology was tested