Comparison of Immunogenicity of Low-Dose Intradermal Hepatitis B Vaccine with the Standard-Dose Intramuscular Vaccination in Young Healthy Iranian Adults

Although hepatitis B vaccine reliably induces immunity against hepatitis B virus (HBV), the cost of intramuscular (IM) vaccination has limited its use, particularly in many developing countries. Intradermal (ID) vaccination has been proposed as a cost-saving alternative method for administration of hepatitis B vaccine. However, the effectiveness of ID vaccination needs to be assessed in different ethnic groups. From September 2006 to March 2008, 185 healthy anti-HBc-negative medical and nursing students at Zahedan University of Medical Sciences who had no history of vaccination against HBV, smoking or hepatitis were evaluated. They were randomly categorized into two groups. In group I (n=91), low-dose (4 |mg) recombinant hepatitis B vaccine (Euvax B, Korea) was given by intradermal route. In group II (n=94), the standard dose (20 mg) of the vaccine was administered intramuscularly at 0, 1, and 6 months. The groups were followed for a minimum of 7 months after the first vaccine dose and tested for anti-HBs titers by ELISA (Diasorin Bio Medica Kit, Saluugia, Italy). Seroprotective anti-HBs titers (titer >10 mIU/mL) were achieved in 79 (87%) students in group I and in 90 (96%) in group II (P=0.031). The difference was much pronounced when the two groups were compared for achieving an anti-HBs titer >300 mIU/mL (P<0.0001). Although ID administration of 4-mg recombinant hepatitis B vaccine is effective, this route is less effective with lower immune response than the IM vaccination.