Abstract
People with Cystic Fibrosis (CF), especially solid organ transplant recipients, have been prioritized in the SARS-CoV-2 vaccination program. This study assesses antibody response of patients with CF who have undergone liver (CF-LI) or lung (CF-LU) transplantation, and compares results to published data of patients with solid organ transplantation without CF as underlying disease. Antibodies against the spike receptor-binding domain were measured within the routine visits at the CF Centre in Innsbruck, Austria, after the second and third doses of SARS-CoV-2 mRNA vaccines. We report on 13 adult CF patients who are recipients of solid organ transplant, including five CF-LI and eight CF-LU. Overall, 69% had measurable antibody response after two, and 83% after three doses of SARS-CoV-2 vaccines. In CF-LI, positive serological response amounted to 100% after two and three doses, while CF-LU showed only a 50% and a 71% response rate, respectively. Clear differences are seen between the CF-LI and CF-LU groups in our cohort, with worse response rate for lung transplant recipients. Immune response between CF-LI and CF-LU, therefore, must be considered in a differentiated manner, and the importance of booster vaccination is once more emphasized with these data.