AUTHOR=Memenga Felix , Kueppers Simon Thomas , Borof Katrin , Kirchhof Paulus , Duengelhoef Paul Maria , Barten Markus Johannes , Lütgehetmann Marc , Berisha Filip , Fluschnik Nina , Becher Peter Moritz , Kondziella Christoph , Bernhardt Alexander M. , Reichenspurner Hermann , Blankenberg Stefan , Magnussen Christina , Rybczynski Meike TITLE=SARS-CoV-2 Vaccination-Induced Immunogenicity in Heart Transplant Recipients JOURNAL=Transplant International VOLUME=Volume 36 - 2023 YEAR=2023 URL=https://www.frontierspartnerships.org/journals/transplant-international/articles/10.3389/ti.2023.10883 DOI=10.3389/ti.2023.10883 ISSN=1432-2277 ABSTRACT=

Among heart transplant (HT) recipients, a reduced immunological response to SARS-CoV-2 vaccination has been reported. We aimed to assess the humoral and T-cell response to SARS-CoV-2 vaccination in HT recipients to understand determinants of immunogenicity. HT recipients were prospectively enrolled from January 2021 until March 2022. Anti-SARS-CoV-2-Spike IgG levels were quantified after two and three doses of a SARS-CoV-2 vaccine (BNT162b2, mRNA1273, or AZD1222). Spike-specific T-cell responses were assessed using flow cytometry. Ninety-one patients were included in the study (69% male, median age 55 years, median time from HT to first vaccination 6.1 years). Seroconversion rates were 34% after two and 63% after three doses. Older patient age (p = 0.003) and shorter time since HT (p = 0.001) were associated with lower antibody concentrations after three vaccinations. There were no associations between vaccine types or immunosuppressive regimens and humoral response, except for prednisolone, which was predictive of a reduced response after two (p = 0.001), but not after three doses (p = 0.434). A T-cell response was observed in 50% after two and in 74% after three doses. Despite three vaccine doses, a large proportion of HT recipients exhibits a reduced immune response. Additional strategies are desirable to improve vaccine immunogenicity in this vulnerable group of patients.