Abstract
BACKGROUND: SARS-CoV-2 vaccination induces a varied immune response among persons with chronic liver disease (CLD) and solid organ transplant recipients (SOTRs). We aimed to evaluate the humoral and T-cell-mediated immune responses to SARS-CoV-2 vaccination in these groups. METHODS: Blood samples were collected following the completion of a standard SARS-CoV-2 vaccination (2 doses of either BNT162b2 or mRNA-12732), and a subset of patients had a blood sample collected after a single mRNA booster vaccine. Three separate methods were utilized to determine immune responses, including an anti-spike protein antibody titer, neutralizing antibody capacity, and T-cell-mediated immunity. RESULTS: The cohort included 24 patients with chronic liver disease, 27 SOTRs, and 9 controls. Patients with chronic liver disease had similar immune responses to the wild-type SARS-CoV-2 compared with controls following a standard vaccine regimen and single booster vaccine. SOTRs had significantly lower anti-S1 protein antibodies (p < 0.001), neutralizing capacity (p < 0.001), and T-cell-mediated immunity response (p = 0.021) to the wild-type SARS-CoV-2 compared with controls following a standard vaccine regimen. Following a single booster vaccine, immune responses across groups were not significantly different but numerically lower in SOTRs. The neutralization capacity of the B.1.1.529 Omicron variant was not significantly different between groups after a standard vaccine regimen (p = 0.87) and was significantly lower in the SOTR group when compared with controls after a single booster vaccine (p = 0.048). CONCLUSION: The immunogenicity of the SARS-CoV-2 vaccine is complex and multifactorial. Ongoing and longitudinal evaluation of SARS-CoV-2 humoral and cellular responses is valuable and necessary to allow frequent re-evaluation of these patient populations.