Serological response to sars-cov-2 vaccines in liver transplant patients

Introduction.Solid organ transplant recipients were excluded from the pivotal clinical trials of COVID-19 vaccines.Therefore, the safety and efficacy data of the different types of available vaccines in this susceptible population is scarce.The goal of the present analysis was to evaluate the humoral response to the COVID-19 vaccines in orthotopic liver transplant (OLT) recipients.Methods.Participants were included from February to September 2021.No prioritized vaccination was performed for OLT patients, and they were included in the regular schedule according to age and place of residency.Controls were otherwise healthy people, mainly family members of patients.All subjects completed the full vaccination schemes, and blood samples were taken after at least 15 days of the complete vaccine doses.The samples were analyzed according to the manufacturer instructions using Liaison XL platform from DiaSorin, LIAISON ® SARS-CoV-2 S1/S2 IgG (DiaSorin S.p.A., Italy), and SARS-COV-2 IgG II Quant (COV-2 IgG II) (Abbott Diagnostics, IL, USA).Results.In all, 187 participants (133 OLT, 54 controls, median age: 60 years, 58.8% women) were included for the analysis; 74.3% had at least one comorbidity (31.6% had hypertension, 32.6% diabetes, 7% neoplasia, and 23% obesity).By vaccine brands, 50.3% received Pfizer-BioN-Tech, 13.9% received Oxford-AstraZeneca, 10.7% received Sinovac, 7.0% Cansino; 16% Sputnik-V and 2.1% received Moderna.The serologic response in OLT patients was lower than in controls (median 549 AU/mL vs. 3450 AU/mL, respectively; p 0.001).A positive humoral response was found in 133 OLT individuals: 89.2% with Pfizer-BioNTech, 60% Oxford-AstraZeneca, 76.9% Sinovac, 55.6% Cansino, 68.2% Sputnik-V, and 100% with Moderna.In controls, only Cansino had a 75% humoral response; all other vaccines had a 100% response.In a multivariable model adjusted for relevant confounders, the antecedent of COVID-19 and Pfizer-BioNTech inoculation were associated positively with the serologic response, while the use of prednisone (compared with other immunosuppressants) interfere with this response.Conclusion.The serologic response to COVID-19 vaccines in OLT patients is lower than otherwise healthy controls.In these patients, the Pfizer-BioNTech vaccine was associated with a higher serologic response.Other variables significantly associated with the humoral response were the COVID-19 antecedent (positively) and prednisone exposure (negatively).At the moment, further analysis is necessary to determine whether this serological response is associated with SARS-COV2 infection or reinfection.