SARS‐CoV‐2 Vaccine Response in Lung Transplant Recipients: A French Multicenter Study

PURPOSE: Many scientific societies recommend SARS‐CoV‐2 vaccination for solid-organ transplant recipients. The immunogenicity of two or three vaccine doses in lung transplant (LTx) recipients is unclear. The aim of this study was to evaluate the humoral response to the vaccine in LTx and heart-lung transplant (HLTx) recipients. METHODS: We conducted a prospective study of LTx and HLTx recipients at seven centers in France. Anti-spike-protein antibody titers after two or three SARS‐CoV‐2 vaccine injections were measured. RESULTS: We studied 2186 patients (1091 [51%] males) with a median age of 49 [45-55] years. Double LTx was performed in 1792 (82%) patients. The main reasons for LTx were chronic obstructive pulmonary disease (n=656, 30%), fibrosis (n=459, 21%), and cystic fibrosis (n=350, 16 %). Median time from LTx to vaccination was 59 [29-108] months and mean time from the last vaccine dose to serological testing was 3 months [1.5-3.8]. We used WHO definitions to classify antibody titers as negative (&lt. 30 BAU/mL), suboptimal (30-260 BAU/mL), or protective (&gt 260 BAU/mL). Of the first 1081 patients, 270 (25%) were partially vaccinated and 649 (60%) fully vaccinated (three doses or history of COVID-19 then two doses); Among these patients,133 (12%) were infected by covid. Of the 649 fully vaccinated patients, 461 (71%), 84 (13%), and 97 (15%) had negative, suboptimal, and protective antibody titers, respectively. The proportion of patients with protective titers was 8% vs. 18% in patients vaccinated within 5 years vs. 5 or more years after LTx, respectively. Among covid-infected patients, 48% developed a protective rate, whether fully or partially vaccinated. CONCLUSION: LTx recipients usually fail to develop protective antibody titers in response to SARS-CoV-2 vaccination. Once further data are collected, we will seek to identify risk factors for a poor antibody response.