Revaccination of renal transplant and hemodialysis recipients with pneumococcal vaccine.

Two years after pneumococcal vaccine was given to patients on a university renal transplant and hemodialysis service, vaccine failures began to occur. Serologic studies showed a threefold decrease in antibody levels during this period, from 913 ng of antibody nitrogen per milliliter to 315 ng/mL. The decrease was greater in patients undergoing hemodialysis than in renal transplant recipients (879 to 215 ng/mL vs 932 to 385 ng/mL). The lowest antibody levels were to types 4, 6A, and 19F. Patients were revaccinated, without serious reactions, and pneumococcal infections decreased as they had after the original vaccination program. After revaccination, there was a twofold increase in antibody levels (315 to 602 ng/mL), but the levels did not reach those seen after primary vaccination. The increase was greater in hemodialysis than in renal transplant recipients (215 to 757 ng/mL vs 385 to 536 ng/mL). This experience indicates that pneumococcal vaccines may be effective in patients undergoing hemodialysis and in asplenic renal transplant recipients, but these groups will require revaccination sooner than normal subjects to maintain immunity.