P12.40.a Immunogenicity of Covid-19 Booster and Seasonal Influenza Vaccination in Primary Brain Tumor Patients: A Prospective Cohort Study

BACKGROUND Patients with primary brain tumors are immunocompromised due to radiation therapy, chemotherapy, and immunosuppressive treatments. However, data on the serological response to COVID-19 booster vaccination in this population remain limited. MATERIAL AND METHODS Primary brain tumor patients eligible for a COVID-19 booster were screened between May and September 2023. Blood samples were collected before and 30 ± 2 days after receiving COVID-19 and seasonal influenza vaccines. Healthy healthcare professionals and relatives served as controls. Statistical analyses included Student t-tests, and multiple regression analysis. RESULTS 37 primary brain tumor patients and 19 healthy controls were included. Median baseline anti-SARS-CoV-2 spike antibody were similar between groups. Following booster vaccination, median antibody titers increased to 14,228 BAU/ml (IQR: 12,326-16,913) in the brain tumor and 13,266 BAU/ml (IQR: 9280-21,100; p = 0.7834) in the control group. Two patients were non-responders. No clinical or laboartory predictors of high post-booster titers (>15,000 BAU/ml) were identified. Influenza A and B immune responses were comparable between groups. CONCLUSION Despite immunosuppression, patients with primary brain tumors show a strong immune response to the COVID-19 booster, indicating effective immunogenicity.