Hepatitis B in haemodialysis: vaccination against HBS antigen

Institut Pasteur Production vaccine, prepared from plasma of chronic carriers of HBsAg (ad + ay sub-types) negative for HBeAg, inactivated by formaldehyde, containing 5 microgram HBsAg per 1ml dose, with Al (OH)3 as adjuvant, was tested in a multicentric efficacy trial. After informed consent and exclusion of subjects positive for HBsAg, anti-HBc or anti-HBs, 367 permanent staff members and 138 chronic haemodialysis patients from 64 centres were enrolled in the trial. They received randomly, double-blind, 3 subcutaneous doses of either vaccine (V) or placebo (P) at one-month intervals and were followed monthly for one year. The incidence of HBV infections was significantly lower in V than in P recipients, in staff and in patients. In staff members, no HBV infections occurred in V recipients after the second injection, whereas they were distributed throughout the whole 12 month follow-up period in P recipients. Anti-HBs titres greater than or equal to 10mIU/ml were obtained in 94% of vaccinated subjects. Antibody peak (mean +/- 2 SE) reached 2433 +/- 1077mIU/ml two months after the third injection, with a further rise to about 30 times this value following a booster injection, 16 +/- 2 months after the first injection. These results demonstrate the immunogenicity and efficacy of Institut Pasteur Production hepatitis B vaccine.