Immunization of hospital personnel with low-dose intradermal hepatitis B vaccine.

Hepatitis B (HB) is an occupational hazard among health care workers. The only hope of control is by the use of vaccines. We evaluated the efficacy of HB vaccine, given intradermally to 304 hospital staff members. Two plasma-derived vaccines were used (Merck, Sharpe & Dohme (MSD), USA; Cheil Sugar & Co., South Korea). Both vaccines gave comparable, satisfactory results, the MSD vaccine inducing anti-HBs in 83% of those vaccinated and Cheil Sugar vaccine inducing anti-HBs in 86%. More than 50% developed anti-HBs titres in excess of 1000 mIU ml-1. The vaccines were well tolerated and there were no serious side effects. A good immune response was found when the vaccine was comparatively fresh but there was tapering of response when the vaccine neared the expiry date. The 0.1 ml dose by the intradermal route is safe, cost-effective and suitable for immunization of health care workers in developing countries such as India.