Effect of supplementary vaccination in healthy non-responders to hepatitis B vaccination.

Among 831 healthy hospital employees vaccinated in accordance with a standard hepatitis B vaccination schedule (three doses of 20 micrograms i.m.), we found 38 (4.6%) hypo- and non-responders with an anti-HBs level less than 10 IU/l. Additional vaccinations with up to three standard doses of hepatitis B vaccine were given to 26 individuals, nine of whom developed anti-HBS titers higher than 10 IU/l after one additional vaccination. Two subjects received no further vaccination. The remaining group of 15 persons were given 2 more injections. After six vaccinations, nine subjects had an anti-HBs response of more than 10 IU/l, while six still had no detectable anti-HBs. In conclusion, supplementary vaccination of healthy hypo- and non-responders after standard hepatitis B vaccination induced an anti-HBs titer greater than 10 IU/l in 38% after one and in 75% after three additional doses of 20 micrograms of hepatitis B vaccine given intramuscularly.