Immunogenic effect of inactivated hepatitis B vaccine: comparison of 20 microgram and 40 microgram doses

The immunogenic effect of inactivated hepatitis B vaccine (Merck Heptavax B) was evaluated in 202 seronegative healthy medical personnel. Three inoculations of vaccine were given at 1-month intervals. Of 116 vaccinees who received a 40-microgram dose, 39% had an anti-HBs response 1 month after the first dose, 88% 1 month after the second dose, and 99% 1 month after the third dose. Of 86 vaccinees who received a 20 microgram dose, 40% had an anti-HBs response 1 month after the first dose, 79% after the second dose, and 95% after the third dose. These results confirm the high immunogenic effect of a 20-microgram dose of vaccine.