Adrian Wiestner, MD, PhD, National Institutes of Health, Bethesda, MD, discusses results from studies examining the impact of BTK inhibitors in vaccine response for patients with chronic lymphocytic leukemia (CLL), in light of the COVID-19 pandemic. Dr Wiestner explains that patients treated with BTK inhibitors have lower response rates to both the shingles Shingrix vaccine and the Hepatitis B vaccine in comparison to treatment-naïve patients with CLL. Dr Wiestner further reports that patients receiving BTK inhibitors do not respond to the Hepatitis B vaccine, commenting that similar results are seen with the COVID-19 vaccine, and suggests potential strategies including a booster vaccine or treatment interruption to improve response to the vaccine. Dr Wiestner highlights that clinical trials to investigate these strategies in patients with CLL are necessary. This interview took place at the 19th International Workshop on Chronic Lymphocytic Leukemia (iwCLL) Biennial Meeting, held virtually in 2021.