Humoral response to two doses of the mRNA-1273 vaccine in Taiwanese liver transplant recipients unaffected by antimetabolites: A single-institute experience

Abstract

Abstract Background Data on the immunogenicity of mRNA vaccines in solid transplant recipients are emerging; however, data on liver transplant recipients of Taiwanese ethnicity remain limited. Methods We recruited 33 Taiwanese liver transplant recipients who received two doses of the Moderna mRNA-1273 vaccine and obtained blood samples for the semiquantitative determination of antibodies to the severe acute respiratory syndrome coronavirus 2 S protein RBD (receptor-binding domain) 2 weeks after each vaccination. The participants were also required to note any adverse events 1 week after the booster vaccination. Results Antibody response after the priming and booster doses of the mRNA-1273 vaccine was 50% and 100%, respectively. The participants were further stratified into optimal (n = 27, >250 U/mL) and inadequate (n = 6, <250 U/mL) response groups according to the upper limit of the numeric antibody titer. A shorter time after transplantation and lower estimated glomerular filtration rate were significantly associated with an inadequate titer. The postvaccination humoral response seemed unaffected by use of antimetabolites. No severe adverse events were reported. Conclusions The postvaccination immunogenicity of Taiwanese liver transplant recipients was satisfactory, whereas the reactogenicity to the novel vaccine was minimal.