ABSTRACT
Immunogenicity of plasma derived hepatitis B vaccine; serological markers (HBsAg; anti HBc and anti HBs) were determined in 432 hospital employees by the Hepanostika microenzyme linked immunoassay method (ELISA) using kits obtained from Organon Technika Laboratories (Holland). Three doses of Pasteur plasma derived vaccine (Hevac B); containing 4 mcg of HBsAg; were administered intramuscularly at one month intervals to 80 of the 102 marker negatives. A booster dose was given at one year. Hepatitis B markers (HBsAg; anti HBc and anti HBs) were determined at 4; 12; 13 and 24 months by ELISA method. Titration for anti HBs were performed at T4; T12 and T13 by the radio-immunoassay method. Of 80 vaccinees; 2 discontinued after the first injection. Sero-conversion to anti HBs occured at 4 months in 57 0f 80 (71.3 per cent); at 12 months in 64 of 73 tested (87.7 per cent) and at months 13 and 24 in 66 and 69 tested (95.6 per cent). Protective levels of anti HBs were achieved in titrated sera collected from sero-converters in 89 per cent; 88.5 per cent and 100 per cent at months; 4; 12 and 13 respectively. No vaccinee developed any evidence of hepatitis B infection during the two years of follow up. A female developed generalized skin rash and a pregnant woman aborted; both following the first injection. The authors conclude that derived hepatitis B vaccine administered to adult Ethiopian hospital personnel is highly immunogenic and protective with minimal side effects