Background: Due to potentially immune-escaping virus variants and waning immunity, a third SARS-CoV-2 vaccination dose is increasingly recommended. However, data in patients with cancer are limited. Patients and methods: We measured anti-SARS-CoV-2 spike protein antibody levels after the third vaccination dose in 439 patients with cancer and 41 health care workers (HCW) at an academic center in Austria and a rural community hospital in Italy. Adverse events were retrieved from questionnaires. Results: Overall, 439 patients and 41 HCW were included. SARS-CoV-2 infections were observed in 62/439 (14.1%) patients before vaccination and in 5/439 (1.1%) patients after ≥1 dose. Longitudinal analysis revealed a decrease of antibody levels between 3 and 6 months after second vaccination in patients with solid tumors (p<0.001) and hematological malignancies without anti-B cell therapies (p<0.001). After the third dose, anti-S levels increased as compared to the first/second dose. Patients receiving B cell-targeted agents had lower antibody levels than patients with hematological malignancies undergoing other treatments (p<0.001) or patients with solid tumors (p<0.001). Moreover, anti-S levels correlated with CD19+ (B cell) and CD56+ (NK cell) counts in peripheral blood. The most frequent adverse events after the third dose were local pain (75/160, 46.9%), fatigue (25/160, 15.6%), and fever/chills (16/160, 10.0%). Patients with cancer had lower anti-S levels than HCW (p=0.015).

Fuente: European Journal of Cancer
Available online 7 February 2022