Uptake of the first to fifth doses of coronavirus disease 2019 vaccine in individuals with chronic lymphocytic leukaemia: A nationwide cohort study in Sweden.

Objectives: Patients with chronic lymphocytic leukaemia (CLL) have an increased risk of severe coronavirus disease 2019 (COVID-19) as well as impaired responses to COVID-19 vaccination, which may be overcome by repeated booster vaccinations. Our objective was to explore the uptake of the COVID-19 vaccine in this population since records of this are scarce. Methods: In this nationwide cohort study, we used multiple population-based health and sociodemographic registries to study COVID-19 vaccine uptake in individuals with CLL in Sweden, from 27 December 2020 to 28 February 2023. Results: A total of 6304 individuals were included. The cumulative incidence (95% confidence interval) at the end of the study period was 95%, 94%, 88%, 78% and 56% for the first, second, third, fourth and fifth doses, respectively. The uptake was significantly higher compared with the age-standardized nationwide uptake. However, there were large disparities, especially for the fourth and fifth doses, across different age groups, birth regions, and income quartiles. These differences were especially pronounced in intersectional analyses, where individuals born abroad in the lowest income quartile had a vaccine uptake of only 49% and 24% for the fourth and fifth doses, respectively. Conclusions: Even though uptake was generally high in individuals with CLL, it seems to be declining from dose three and onwards, and there are significant sociodemographic disparities in vaccine uptake.