Safety and efficacy of bnt162b2 mrna vaccine among liver transplant recipients

ABSTRACT

Background: BNT162b2 mRNA vaccine has been shown to be safe and effective in healthy subjects. The safety and efficacy of this vaccine in liver transplant (LT) recipients is still a subject of evaluation. The objective of this study was to assess the safety and efficacy of BNT162b2 mRNA vaccine among LT recipients. Methods: Immune response of two dose of BNT162b2 mRNA vaccine in 76 LT recipients was compared to 174 age-matched immunocompetent subjects with no exposure to SARS-CoV-2 infection. Postvaccination IgG antibodies against the RBD of SARS-CoV-2 IgG S-protein serology and neutralizing antibodies (NA) to the BNT162b2 mRNA vaccine were determined at least 14 days after the second dose of vaccine. AB titer ≥1.1 was considered protective. Side effects were monitored during study period. Results: Following the administration of the BNT162b2 mRNA two dose vaccines, LT recipients (median age 64 (range 22-83 years), 56.6% males) showed reduced immune response as compared with immunocompetent controls (72% vs. 94.2%, p<0.0001). The geometric mean of titer IgG antibody of SARS-CoV-2 and NA was significantly lower in LT recipients who received combine immunosuppression (combination of CNI and prednisone, and/or MMF and/or everolimus) vs CNI monotherapy 1.1±3.1 vs. 3.5±2.1, p<0.0001, 59.0±3.2 vs. 256.0±4.7, p=0.002. In multivariate analysis, the antibody response was reduced in LT recipients who received combined immunosuppression and in those with impaired renal function. Overall most self-reported side effects that were detected in 39 (51%) LT recipients were mild. The immune response did not correlate with more severe side effects. The side effects occurred more often in women than in men. Conclusion: Compared with immunocompetent subjects, liver transplant recipients had reduced immune response. Factors affecting serological antibodies response include renal function and type of immunosuppression used. Side effects were mild in most cases and more often in women. The durability of immune response to BNT162b2 mRNA vaccine among LT recipients needs further investigation.