ABSTRACT
There is an increased mortality risk in COVID-19 infected lung transplant (LTx) patients. SARS-CoV-2-specific IgG antibody response after vaccination is impaired in LTx patient, most likely due to intensive immunosuppressive therapy. Whether a five-dose regime of COVID-19 vaccines in LTx patients results in an increased antibody response is not known. Therefore we studied the serological IgG antibody response, and risk factors for non-response after a five-dose regime of COVID-19 vaccines. In this single center retrospective cohort study, IgG antibody response were assessed after 2-5 mRNA-based COVID-19-vaccine in all vaccinated LTx patients between February 2021 and September 2022. Vaccine response was defined as an IgG level above 300 BAU/ml. Antibody responses due to COVID-19 infection were excluded from the analysis. Mann-Whitney U-test and chi-squared test were used to compare clinical parameters and outcomes between responders and non-responders. Of 294 LTx patients IgG antibody responses after 2-5 vaccinations were analyzed. IgG antibody response to COVID-19 vaccination was found in 15% of the LTx patients after 2 vaccines, in 38% after 3 vaccines, in 49% after 4 vaccines and in 59% after 5 vaccines. 246/492 (50%) of the vaccinated individuals tested positive for SARS-CoV-2 during the study period. The COVID-19 related mortality was 1,4 % (4/294), all 4 patients were non-responders. Factors associated with COVID-19 vaccine response are shown in table 1. For the total group COVID-19 related hospitalization was not significantly higher in non-responders (p = 0.208). Risk factors associated with non-response to COVID-19 vaccines were renal impairment, defined as EGFR < 60 ml/min/1,73 m2 (p = 0.007) and older age (p = 0.009). A five-dose regime of COVID-19 vaccines in LTx patients increases the IgG antibody levels and results in a vaccine response in 59% of the LTx population. Therefore, continuing to vaccinate LTx patients without a response seems to be beneficial. [ABSTRACT FROM AUTHOR] Copyright of Journal of Heart & Lung Transplantation is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)