This pharmaco-epidemiological study aims to assess the safety and tolerance of COVID-19 vaccines in cancer patients undergoing immunotherapy. Given the heightened risk of severe COVID-19 in this population, the findings could significantly influence vaccination strategies and guidelines for cancer patients. The study's results may enhance the competitive positioning of vaccine manufacturers by providing real-world data on vaccine safety in immunocompromised populations, potentially leading to increased adoption and market share. Additionally, the outcomes could inform future clinical practices and regulatory policies, impacting the overall market landscape for both immunotherapy and vaccine development.