Intramuscular vs intradermal route for hepatitis B booster vaccine in celiac children.

aimTo compare intradermal (ID) and intramuscular (IM) booster doses, which have been used in healthy and high risk subjects, such as healthcare workers, haemodialysis patients, human immunodeficiency virus patients, and renal transplant recipients unresponsive to initial hepatitis B vaccination, in celiac individuals.

methodsWe conducted our study on 58 celiac patients, vaccinated in the first year of life, whose blood analysis had showed the absence of protective hepatitis B virus (HBV) antibodies. All patients had received the last vaccine injection at least one year before study enrolment and they had been on a gluten free diet for at least 1 year. In all patients we randomly performed an HBV vaccine booster dose by ID or IM route. Thirty celiac patients were revaccinated with recombinant hepatitis B vaccine (Engerix B) 2 μg by the ID route, while 28 celiac patients were revaccinated with Engerix B 10 μg by the IM route. Four weeks after every booster dose, the anti-hepatitis B surface (HBs) antibody titer was measured by an enzyme-linked immune-adsorbent assay. We performed a maximum of three booster doses in patients with no anti-HBs antibodies after the first or the second vaccine dose. The cut off value for a negative anti-HBs antibody titer was 10 IU/L. Patients with values between 10 and 100 IU/L were considered "low responders" while patients with an antibody titer higher than 1000 IU/L were considered "high responders".

resultsNo significant difference in age, gender, duration of illness, and years of gluten intake was found between the two groups. We found a high percentage of "responders" after the first booster dose (ID = 76.7%, IM = 78.6%) and a greater increase after the third dose (ID = 90%, IM = 96.4%) of vaccine in both groups. Moreover we found a significantly higher number of high responders (with an anti-HBs antibody titer > 1000 IU/L) in the ID (40%) than in the IM (7.1%) group, and this difference was evident after the first booster dose of vaccination (P < 0.01). No side effects were recorded in performing delivery of the vaccine by either the ID or IM route.

conclusionOur study suggests that both ID and IM routes are effective and safe options to administer a booster dose of HBV vaccine in celiac patients. However the ID route seems to achieve a greater number of high responders and to have a better cost/benefit ratio.