The Duration of Humoral Immunity and the Memory Cell Function After Vaccination With 7-valent Pneumococcal Conjugate Vaccine in CLL

Patients with chronic lymphocytic leukemia (CLL)have had very poor humoral responses to pneumococcal polysaccharide vaccine (PPV). The vaccine in which pneumococcal polysaccharide antigens are conjugated to protein (PCV) have been immunogenic in CLL patients in our previous studies.

The purpose of this study is to evaluate the duration of these vaccine-induced antibodies and the function of memory cells by giving a one dose of PPV-vaccine after several years of PCV-vaccination.

Inclusion Criteria:

• CLL patients and controls who have been vaccinated with PCV in our previous study

Exclusion Criteria:

• Vaccinated with PPV-vaccine within the last 5 years, immunoglobulin substitution, corticosteroid treatment (equivalent of 20mg prednisolone per day)