Background: Pneumococcal vaccination has been recommended for immunocompromised children over 2 years including patients with chronic renal disease. However, the effect of vaccination and revaccination is variable and the indication for immunization is a subject of controversy.
Methods: Forty children and young adults with chronic renal diseases (including the idiopathic nephrotic syndrome, chronic renal failure, patients undergoing dialysis and after transplantation) were vaccinated with a 23-valent pneumococcal vaccine. The efficacy of the vaccine was evaluated by measuring antibody titres before and 4 weeks, 6 months, and 12 months after vaccination. Twenty-two patients were submitted to a revaccination 1 year after the first vaccination.
Results: A sufficient immune response, defined as an at least fourfold increase of postvaccinal antibody titres and an antibody titre > 200, was observed in 83% of the patients 4 weeks after vaccination, but only in 68% after 6 months, and in 48% after 1 year. Revaccination produced a significant immune response in 11/22 patients (50%) followed by a rapid decline of antibody levels within 6 months. Both vaccinations were well tolerated.
Conclusions: The currently available vaccine is without major side-effects and effective in producing a significant immune response. Antibody levels should be monitored in vaccinated patients with chronic renal diseases considering the rapid decline as early as 6 months after vaccination. Evaluation of the efficacy of revaccination in these patients requires further investigations.