COMPARATIVE EFFECTOF INTRADERMAL AND INTRAMUSCULAR INJECTIONS OF HEPATITIS B VACCINE

Background – Hepatitis B virus is one of the most common causes of chronic liver disease, cirrhosis and liver carcinoma, and prophylaxis with vaccination is of utmost importance. The present study was conducted to compare the effectiveness of intradermal and intramuscular injection of hepatitis B vaccine. Methods – Two-hundred female high school students entered this double-blind randomized clinical trial performed in Kashan (a city in the center of Iran) in 1996–97. A 5-mL blood sample was obtained and checked for hepatitis B surface antigen (HBsAg) and antibodies to the HBsAg (HBsAb) using an enzyme-linked immunosorbent assay (ELISA). Subjects were allocated to one of three age groups and randomly assigned to receive intramuscular (control; 1 mL recombinant hepatitis B vaccine) or intradermal (case) vaccine (0.1 mL recombinant hepatitis B vaccine) in the deltoid region at months 0, 1, and 6. Three weeks after the last vaccination, the HBsAb level was measured by ELISA. Results – Intramuscular injection resulted in 97.6% positive, 1.2% mild, and 1.2% negative responses, respectively, whereas intradermal injection resulted in 93.7% positive, 2.1% mild, and 4.2% negative responses, respectively. This difference was not statistically significant (p = 0.23). Conclusion – Due to a very small difference in the effectiveness of the two injection methods and the cost-effectiveness of the intradermal injection, intradermal injection could be safely substituted for intramuscular injection.