Immune response of subjects at high risk of hepatitis B to a new genetically engineered hepatitis B vaccine administered in low doses by the intradermal route.

Fifty-eight subjects at high risk for hepatitis B were vaccinated with hepatitis B vaccine prepared by a DNA recombinant technique (Engerix B- Smith-Kline Biologicals) by the intradermal route with low doses (5 microgr) at 0, 15, 30 and 45 days on the volar surface of the arms. A positive immune response (100%) was found in all children (5 affected by thalassemia, 5 affected by sickle cell anaemia, 9 affected by neurological handicaps) and in all healthy medical staff. None showed side-effects and the small pigmented macula following vaccination disappeared after a few months. Since the World Health Organization proposed a program of mass vaccination in highly endemic areas for hepatitis B, the authors suggest that the use of the new engineered vaccine in low doses by the intradermal route could represent an effective strategy to realize this project.