Acceptance of SARS-CoV-2 vaccination among patients with cancer undergoing immunosuppressive therapy: Portuguese study

ABSTRACT

Background: Until April 2021, WHO declared more than 140 million cases and 3 million deaths due to COVID-19. To effectively control the pandemic, a significant part of the population has to acquire immunity, which is best achieved through vaccination. None of the clinical trials evaluating the effectiveness and safety of the vaccines included cancer patients. This study aimed to evaluate the acceptance of the COVID-19 vaccine by cancer patients undergoing immunosuppressive therapy in a Portuguese cancer centre. Methods: Unicentric, cross-sectional survey conducted on cancer patients with a solid malignancy under chemotherapy, targeted agents or immunotherapy, between March and April 2021. Results: We included 169 patients (109 female;60 male) with a median age of 61 years old (29-82). More than half (n=105;62.1%) had a lower literacy degree, 97 (57.4%) lived in the countryside. The majority of the patients were receiving palliative treatment (n=87;51.5%). Most of the patients intended to be vaccinated (n=142, 84.0%), 24 (14.2%) were unsure and 3 (1.8%) did not. All the negative answers were given by patients receiving palliative treatment. Logistic regression analysis revealed that high school qualification (p=0.007), divorced status (p= 0.037), rural residence (p=0.047), and believing in the vaccine (p=0.001), had a statistically significant effect on the probability of the patients wanting to be vaccinated. The most frequent reasons for wanting to be vaccinated were the sense of collective responsibility and the fear of having severe disease. The most frequent reasons for not wanting to be vaccinated were the lack of evidence and the wish to wait for the end of treatment. The need for more information on effectiveness and safety were the main reasons for uncertainty related to the vaccine. Conclusions: Despite the lack of information regarding efficacy, duration of immunity and timing of vaccination in cancer patients under immunosuppressive therapy, this study demonstrated that the majority of patients intend to be vaccinated against COVID-19. These results were related to residence type, literacy and belief in the effectiveness of the vaccine. The higher acceptance rate in our study when compared with other studies must be noted. Legal entity responsible for the study M.J.P. de Sousa. Funding: Has not received any funding. Disclosure All authors have declared no conflicts of interest.