An
alum bivalent
hepatitis B vaccine containing 5 micrograms/dose of
formalin-inactivated and purified
HBsAg has been prepared from plasma of
HBeAg negative donors. Safety of the product has been controlled by compulsory testing of each batch in susceptible chimpanzees. This
vaccine (HB
vaccine) was used for the prophylaxis of
Hepatitis B in hospital staff working in high-risk settings and patients undergoing periodic dialysis since the Autumn of 1975. Tolerance to the HB
vaccine was excellent both in staff and patients as assessed by a nation-side survey on a thousand vaccinees. More than 96% of the staff developed protective levels of anti-HBs after three
injections of
vaccine given at one month intervals and became fully immune from HBV
infection. A booster injection given at one year stimulated an anamnestic rise of anti-HBs sufficient to ensure protective levels of antibody for at least five years post-booster. The response of renal patients varied according to the age of recipients: young patients responded equally as well as the healthy staff, while patients over the sixth decade had a lower and delayed response. Because of that, a fourth injection of HB
vaccine was advocated in elderly patients. Dialysis patients who developed anti-HBs either after three or four
injections were fully protected against chronic HBV
infections. Anti-HBs positive donors who had received a single booster injection of HB
vaccine and vaccinees who had received their 12 months booster were both found to be an adequate source of high-titre anti-HBs plasma for preparing hyperimmune anti-HBs
globulin. The HB
vaccine which is manufactured by Institut Pasteur Production under the name
HEVAC B degrees is now used world-wide for the prophylaxis of hospital acquired
infection in developed countries and for the prevention of maternal-infant transmission in the endemic countries of Asia and Africa.