Abstract
Immune checkpoint inhibitors are drugs that keep the immune system strong enough to attack cancer cells. To date, cancer immunotherapy using immune checkpoint inhibitors has been shown to be effective against various types of cancer. During the coronavirus infectious disease-2019 (COVID-19) pandemic, concern is raised whether clinical treatment with immune checkpoint inhibitors can interfere with COVID-19 vaccination in patients with several malignancies. Recent report shows significantly improved anti-tumor efficacy of the combination of anti-programmed cell death protein-1 (anti-PD-1) therapy and chemotherapy in patients with advanced nasopharyngeal cancer (NPC) who received COVID-19 vaccination, however, the incidence of severe immune-related adverse events was similar. However, our results revealed that there is no medical evidence stating that COVID-19 vaccination significantly improved the efficacy of the combination of anti-PD-1 therapy and chemotherapy in patients with advanced NPC. Clinical studies with large cohorts of large numbers of patients are required to clarify the impact of COVID-19 vaccines on the efficacy of cancer immunotherapy with immune checkpoint inhibitors.