Clinical

Study of intradermal hep B vaccine in dialysis patients suggests need for higher doses

Last Updated: 2004-05-20 17:24:38 -0400 (Reuters Health)

NEW YORK (Reuters Health) - In patients on peritoneal dialysis, a low-dose intradermal hepatitis B vaccine is associated with higher early response rates than the conventional intramuscular vaccine, but the difference diminishes at 2 years after vaccination, according to a new study.

In the May issue of the American Journal of Kidney Diseases, Dr. Ka Foon Chau and colleagues at the Queen Elizabeth Hospital in Hong Kong, China explain that rates of seroconversion to the hepatitis B virus vaccine - defined as an anti-HBs titer of greater than 10 mIU/mL - are reported to range from 50% to 73% in patients with renal failure, compared to rates of more than 90% in healthy subjects.

Furthermore, the recommended vaccination protocol for uremic patients involves 4 doses instead of 3, 40 ug per dose instead of 20 ug, and injection into the deltoid muscle.

In a study involving 60 patients on peritoneal dialysis, the investigators sought to determine whether a lower dose of hepatitis B vaccine (5 ug) administered intradermally once weekly for 10 weeks would be as effective as 20 ug administered intramuscularly at 0, 1 and 6 months.

At 6 months after the first dose, "the cumulative seroconversion rate was significantly greater with intradermal vaccination," the researchers report.

After a 2-year observation period, however, there was no difference between the 2 groups in the proportion of patients with anti-hepatitis B surface antigen levels maintained at greater than 10 mIU/ml or greater than 100 mIU/ml, according to the study.

Specifically, at 2 years after the first dose, 57.1% of patients vaccinated intramuscularly and 45.6% of patients vaccinated intradermally had protective antigen levels, defined as anti-hepatitis B surface antigen titers of more than 10 mIU/ml. Only 23.8% in the intramuscular group and 13.6% in the intradermal group had titers above 100 mIU/ml at 2 years.

"It is conceivable that a greater vaccine dose may be required to improve the efficacy of intradermal hepatitis B vaccine vaccination," the authors said.

"Although a greater intradermal vaccine dose is proposed, the total amount of vaccine is still much less than that for conventional intramuscular vaccination for dialysis patients," they write.

Am J Kidney Dis 2004;43:910-917.