IMMUNOGENICITY OF PLASMA DERIVED V ACCINE IN ETHIOPIAN HOSPITAL PERSONNEL

Abstract

ABSTRACT: To study the 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 5 mcg of HBsAg, were administered intramuscularly at one month intervals to 80 of the l02 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 the ELISA method. Titration for anti HBs were pertormed at T 4, T 12, and T 13 by the radio-immunoassay method. Of 80 vaccinees, 2 discontinued after the first injection. Sero-conversion to anti HBs occurred at 4 months in 57 of 80 (71.3% ); at 12 months in 64 of 73 tested (87.7%) and at months 13 and 24 in 66 of 69 tested (95.6%). Protective levels of anti HBs were achieved in titrated sera collected from sero-converters in 89%, 88.5% and 100% 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. We conclude that plasma derive