Long term effect on immune response after pneumococcal vaccination in patients with chronic lymphocytic leukemia and evaluation of the effect of revaccination (KLLVAC-2018)

Chronic lymphocytic leukemia (CLL) patients have an increased risk of pneumococcal infections. Vaccination may reduce the risk, but the immune response is often hampered in CLL patients. Swedish guidelines recommend vaccination with conjugated vaccine (Prevenar13/PCV13) followed by non-conjugated vaccine (Pneumovax/PPSV23) after 8 weeks in CLL patients, but research supporting that strategi is lacking.

In a study 2013-2016, we vaccinated 126 CLL patients at 8 Swedish  hematological departments with PCV13 (n=63) or PPSV23 (n=63). Significantly more patients receiving PCV13 developed protective antibodies after 4 weeks and 6 months.

In this study, we aim to evaluate the remaining immune response 4-6 years after vaccination, and revaccinate with PCV13 and PPSV23, and compare with healthy individuals. The aim of the study is to improve recommended vaccination strategies for CLL patients and reduce the risk of pneumocoocal disease.