Yeast-derived hepatitis B vaccine in dental students. A three-year follow-up study.
Sixty health adults (56 dental students and four post-graduates of the Dental Faculty in Milan; mean age 26.4 years, range 22-42 years) were vaccinated with a recombinant DNA vaccine (Engerix B, Smith Kline and French; 20 micrograms given i.m. at time 0, 1 and 6 months). One month after the third injection, 98.3% (59/60) vaccinees showed anti-HBs at levels higher than 10 mIU ml-1 (geometric mean titre 734.8 mIU ml-1). One year after the beginning of vaccination (i.e. 6 months after the third injection of vaccine), 46 vaccinees showed anti-HBs titre higher than 100 mIU ml-1 (24 between 100 and 1000 mIU ml-1 and 22 higher than 1000 mIU ml-1) and 14 vaccinees had anti-HBs below 100 mIU ml-1 (12 between 10 and 99 mIU ml-1 and 2 below 10 mIU ml-1). Since duration of antibody is directly related to the height of the initial response, the 14 vaccinees with lower anti-HBs titres were given a fourth dose of vaccine. All boosted vaccinees showed a vigorous anti-HBs response and the post-booster anti-HBs GMT increased to 1570 mIU ml-1 compared with 47.8 mIU ml-1 attained before the boosting injection. At three years from the beginning of vaccination, all vaccinees who showed anti-HBs titres higher than 100 mIU ml-1 after the primary vaccination and all but one of the boosted vaccinees were still anti-HBs positive.(ABSTRACT TRUNCATED AT 250 WORDS)
Zanetti
A R
AR
Institute of Virology, University of Milan, Italy.
Tanzi
E
E
Pozzi
A
A
Romano
L
L
Bergamini
F
F
D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D006509:Hepatitis B / Q000517:prevention & control*; D006510:Hepatitis B Antibodies / Q000096:biosynthesis; D006514:Hepatitis B Surface Antigens / Q000235:genetics / Q000302:isolation & purification; D006801:Humans; D007117:Immunization, Secondary; D008297:Male; D012441:Saccharomyces cerevisiae / Q000235:genetics; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D014761:Viral Hepatitis Vaccines / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*
D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D014614:Vaccines, Synthetic; D014761:Viral Hepatitis Vaccines