VERY LOW-DOSE HEPATITIS-B VACCINATION IN THE NEWBORN - ANAMNESTIC RESPONSE TO BOOSTER AT 4 YEARS

Seventy‐eight children who had received three very low doses (1 or 2 μg) of Merck, Sharp, and Dohme (MSD) plasma‐derived vaccine (PDV) in early infancy were followed to approximately four years of age. Of the 70 who had responded to the initial course of vaccine with measurable anti‐HBs, levels had fallen to below 10 mlU/ml in 38% of subjects given 1 μg doses and in 17% of those who had been given 2 μg doses. None of the children were positive for anti‐HBc. Two weeks after a 2 μg dose of MSD recombinant DNA (rDNA) vaccine all subjects had more than 10 mlU/ml of anti‐HBs, with 90% exceeding 1,000 mlU/ml. A response to hepatitis B vaccine in infancy is followed by an effective immunological memory for serveral years, even if anti‐HBs falls to low levels. The rDNA hepatitis B vaccine (MSD) in 2 μg doses is an effective booster following a primary course of plasma derived vaccine. Copyright © 1990 Wiley‐Liss, Inc., A Wiley Company