The purpose of this study is to determine whether 7-valent pneumococcal conjugate vaccine safely induces immune responses and immunological memory in children with idiopathic nephrotic syndrome in remission.

Idiopathic nephrotic syndrome (INS) is the most frequent glomerular disease in children under 16 years old with incidence rate 2-7/100,000 patients/year depending on ethnicity. Those patients are susceptible to invasive pneumococcal disease (IPD) including peritonitis, pneumonia with or without pleural effusion and meningitis. Due to increased mortality and risk of relapses associated with IPD, it has been recommended that children with INS should be immunized with pneumococcal conjugate vaccine [1]. However, concerns on vaccine safety and impaired immunogenicity due to INS pathogenesis and immunosuppressive treatment are a hurdle for universal implementation of existing guidelines.

To thoroughly evaluate safety of 7-valent pneumococcal conjugate vaccine (PCV7) in children with INS in remission, we will investigate a possible association of vaccination with increased risk for recurrences of INS. We will also study immunogenicity and kinetics of immune response in INS patients and healthy subjects and the effect of different types of treatment on primary immune response and antibody persistence at 12-14 months following vaccination with PCV7.

Inclusion Criteria:

• Male or Female
• Between 2-20 years of age

Exclusion Criteria:

• serious allergic reaction to previous vaccination
• history of invasive pneumococcal disease
• vaccination with pneumococcal conjugate vaccine
• vaccination with pneumococcal polysaccharide vaccine
• administration of intravenous immunoglobulin or other blood products during the last 3 months