The Effect of Previous Pneumococcal Immunization on the Immune Response of Patients With Severe CKD to Prevnar 13

Adult patients with severe chronic kidney disease (CKD) are immunocompromised and known to have an increased risk of pneumococcal infection. To prevent the infection, immunization with pneumococcal polysaccharide vaccine (PPV23) is currently recommended in Canada; however, the vaccine effect in these patients is suboptimal because of their immune dysfunction. The second-generation pneumococcal vaccines (polysaccharide-protein conjugate) have superior immunogenicity in some immunocompromised adult individuals. In Canada, Prevnar 13 has recently been recommended by the NACI for certain categories of immunocompromised adults, such as HSCT recipients and HIV-positive patients. However, the NACI has concluded that there is currently insufficient evidence to recommend the use of Prevnar 13 in patients with chronic kidney disease. No published data on the use of pneumococcal conjugate vaccines in adults with CKD are available. Moreover, it is unknown whether a previous immunization with PPV23 may have a negative effect on the immune response to Prevnar 13 in these patients. Such a possibility exists due to the memory B-cells' depletion following immunization with pure polysaccharide antigens. In this case, additional doses of Prevnar 13 may be required to achieve the optimal protection. The conjugate vaccine will then expand the B-cell pool available to respond to subsequent antigen challenge. To test whether previous immunization with PPV23 affects the immune response of severe CKD patients to Prevnar 13, we will immunize two groups of adult stage 4 and 5 CKD patients attending the Thunder Bay Regional Health Sciences Centre with one dose of Prevnar 13 and will assess their initial immunological response, its longevity, and vaccine safety. The first group will consist of patients who had been immunized with PPV23 more than one year prior to the enrollment in this study and the second group will include patients without history of pneumococcal vaccination. Fold increase in antibody levels and OPA, as well as longevity of the immune response over a one-year period will be assessed as the surrogate for protection against pneumococcal infection. The immune response will be analyzed in the context of demographic and clinical characteristics of the vaccinated patients. All infectious episodes in the study participants will be recorded throughout one year of observation. We will also record all vaccine adverse effects following immunization and compare their frequency and severity between the two groups. The anticipated results of this trial will provide essential evidence to justify the use of Prevnar 13 for immunization of adult CKD patients.