Sufferers with detectable neutralizing antibodies in the bad group were more often treated with mycophenolate mofetil/mycophenolic acidity (MMF/MPA) than those in the positive group (20/10 vs 5/11, = 0.022). recipients with Bisoprolol positive neutralizing antibody (nAb) had been present in the sort 1 group. Fourteen and 16 LT recipients with undetected nAb had been present in the sort 2 and Type 3 groupings, respectively. Period from lymphocyte and transplant count number were different among the 3 groupings. The degrees of anti-RBD and anti-S1S2 reduced with lowering neutralizing inhibition prices. Compared to the Type 2 and Type 3 groups, the Type 1 group had an enhanced innate immune response. The proportions of B, DNT, and CD3+CD19+ cells were increased in the Type 1 group, whereas monocytes and CD4+ T cells were decreased. High CD19, high CD8+CD45RA+ cells, and low effector memory CD4+/na?ve CD4+ cells of the T-cell populations were present in the Type 1 group. The Type 1 group had higher concentrations of plasma CXCL10, MIP-1 beta, and TNF-alpha. No severe adverse events were reported in all LT recipients. We identified the immune responses induced by inactivated vaccines among LT recipients and provided insights into the identification of immunotypes associated with the responders. Keywords: SARS-CoV-2 inactivated vaccines, liver transplant recipient, neutralizing antibodies, CD3+ CD19+ cell, CXCL10 Introduction Solid organ transplant (SOT) recipients are at a high risk of SARS-CoV-2 Bisoprolol infection and its severe outcomes (1, 2). Liver transplant (LT) recipients or other immunocompromised patients are a highly vulnerable patient population, requiring SARS-CoV-2 vaccination, as recommended by some societies (3, 4). Due to immunosuppressive treatment effects, lower immune response and fewer detectable SARS-CoV-2 antibodies to the SARS-CoV-2 mRNA vaccine among SOT recipients than among the immunocompetent population have been documented (5C12). Some studies have reported lower immunological and poor antibody response to mRNA-based vaccines among LT recipients (11, 13). Inactivated vaccines have proven to be strongly immunogenic and highly efficient in preventing severe coronavirus disease (COVID-19) in immunocompetent individuals (14C16). However, knowledge of inactivated vaccine-induced humoral and cellular responses in SOT recipients, especially LT recipients, remains poorly understood. Vaccines may prevent infection and its unfavorable effects by inducing robust virus neutralizing antibody (nAb) responses, which are crucial for shaping both humoral and cellular protective immunity during the early response to vaccination (17, 18). In addition to nAb, T cells are critically necessary for clearing viral infections and effective vaccination to maintain extensive and lasting antiviral immunity (19, 20). Our previous study confirmed that T-cell immune response changed during disease progression in patients with COVID-19 (21). Cytokines and chemokines play a key role in the development and maintenance of immunity in response to infection and vaccination. Early cytokine and chemokine signatures may be used to monitor effective vaccination; they have been proposed as guides for optimizing the efficacy of mRNA vaccination strategies (22). Knowledge of the two-dose inactivated SARS-CoV-2 vaccine-induced immune response in LT recipients remains Bisoprolol poor, especially the comprehensive difference in humoral and cellular responses between responders and non-responders. Defining the nature of immune response after SARS-CoV-2 vaccination could help identify biomarkers for predicting the effective application of vaccines in LT recipients. In this study, we used the systems vaccinology approach to comprehensively profile the innate and adaptive immune responses of LT recipients who were vaccinated with the two-dose inactivated SARS-CoV-2 vaccine. Additionally, we evaluated the clinical characteristics, antibody responses, single-cell peripheral immune profiling, and plasma cytokine/chemokine/growth factor levels among LT recipients with SARS-CoV-2 inactivated vaccination. Patients and methods Patient population and study design This study was an observational study conducted among LT recipients who had received two scheduled doses of the inactivated vaccines (CoronaVac or BBIBP-CorV) within 8 weeks, according to the national vaccination protocol. The participants were recruited from an online survey. Three healthy donors without vaccination (HD) and four healthy donors vaccinated with the inactivated vaccine (HDV) were recruited as Bisoprolol the no vaccination healthy RP11-403E24.2 controls and vaccination healthy controls, respectively. Blood samples from LT recipients and HDVs were obtained within 4C8 weeks after administration of the second dose of the vaccine for CyTOF and cytokine detection. The exclusion criteria included age <18 years and history of COVID-19 diagnosis. All the clinical data of LT recipients within 4 weeks before the first dose of the vaccine were retrospectively reviewed. Figure?1A shows the study flow diagram for the study. This study was approved by the Ethics Committee of Beijing YouAn Hospital ([2021]083), and all participants provided written informed consent. Open in a separate window Figure?1 Schematic workflow and SARS-CoV-2 neutralizing antibody detection after vaccination. (A).