BackgroundAt the start of 2021, oncologists lacked the necessary scientific knowledge to adapt their clinical practices optimally when faced with cancer patients refusing or reluctant to be vaccinated against COVID-19, despite the marked vulnerability of these patients to severe, and even fatal forms of this new viral infectious disease. Oncologists at Foch Hospital were confronted with this phenomenon, which was observed worldwide, in both the general population and the population of cancer patients.MethodsBetween April and November 2021, the Ethics and Oncology (...) Departments of Foch Hospital decided to investigate this subject, through an empirical and interdisciplinary study in bioethics. Our scientific objective was to try to identify and resolve the principal bio-ethical issues, with a view to improving clinical practices in oncology during future major pandemics of this kind, from a highly specific bio-ethical standpoint. We used a mainly qualitative methodological approach based on questionnaires and interviews.ResultsIn April 2021, 29 cancer patients refused or were reluctant to be vaccinated. Seventeen of these patients said that making vaccination mandatory would have helped them to accept vaccination. In October 2021, only 10 cancer patients continued to maintain their refusal. One of the main reasons for the decrease in refusals was probably the introduction of the “pass sanitaire” in July 2021, which rendered vaccination indispensable for many activities. However, even this was not sufficient to convince these 10 cancer patients.ConclusionWe identified a key bio-ethical issue, which we then tried to resolve: vaccination policy. We characterized a major tension between “the recommendation of anti-COVID-19 vaccination” and “free will”, and the duty to “protect each other”. Mandatory vaccination, at least in France, could resolve this tension, with positive effects on quality of life, or survival, in cancer patients initially refusing or reluctant to be vaccinated, but only if collective and individual scales are clearly distinguished. (shrink)