Safety of COVID-19 Vaccine in Patients with Cancer in a High-Volume Comprehensive Cancer Center

Background: Few data are available on the safety of COVID-19 vaccines in cancer patients undergoing active cancer-directed treatment. Patients and Methods: This case series analyzes outcomes in terms of adverse events in 5297 patients undergoing anti-cancer treatment who were vaccinated with anti-SARS-CoV-2 Pfizer-BioNTech vaccine at a single cancer center from March 6, 2021 to May 9, 2021. Adverse events were retrieved from the national Italian pharmacovigilance platform (http://www.vigicovid.it). Results: Of the 5297 patients treated for either solid tumors (87%) or onco-hematologic malignancies (13%) who were vaccinated, 8 adverse drug reactions (ADRs) were reported. One was a severe ADR and 7 were non-severe ADRs. Non-severe ADRs resolved within 48 hours. Conclusion: BNT162b2 Pfizer-BioNTech vaccine was safely administered in the largest cohort of cancer patients reported to date.