title: High seroprotection rate induced by low doses of a recombinant hepatitis B vaccine in healthy Iranian neonates.
abstract: Low-dose vaccination has been proposed as a cost-saving strategy to implement mass vaccination of neonates with hepatitis B (HB) vaccine, world-wide, particularly in developing countries. The effectiveness of low vaccine doses, however, needs to be evaluated and verified in newborns from different ethnic backgrounds. In this study, a recombinant HB vaccine (Heberbiovac) was administered in three different doses, including the standard 10 microg together with 5 and 2.5 microg to three groups of healthy Iranian neonates. Each group, consisting of 230-260 subjects, received triple doses of vaccine given i.m. at 0, 1.5 and 9 month intervals. Serum samples were collected 2-4 weeks after completion of vaccination, and anti-HBs antibody was quantitated by a sandwich ELISA. Seroprotection (anti-HBs>10 IU/L) was detected in 92, 97.4 and 96.1% of 2.5, 5 and 10 microg vaccine dose recipients, with geometric mean titer (GMT) of 4502, 5824 and 6104 IU/L, respectively. No significant differences were observed in seroprotection rate and GMT between the 10 and 5 microg dose recipients. Both parameters, however, were significantly lower in neonates vaccinated with a 2.5 microg vaccine dose (P<0.05 and P<0.001, respectively). These findings indicate induction of a strong protective immune response in healthy Iranian neonates by a low dose (5 microg) of the recombinant HB vaccine.
authors.affiliation: Department of Immunology, School of Public Health, Tehran University of Medical Sciences, PO Box 6446-14155, Tehran, Iran.
authors.forename: F
authors.initials: F
authors.lastname: Shokri
authors.forename: A
authors.initials: A
authors.lastname: Jafarzadeh
mesh_terms: D004306:Dose-Response Relationship, Immunologic; D005260:Female; D006509:Hepatitis B / Q000517:prevention & control*; D006510:Hepatitis B Antibodies / Q000096:biosynthesis / Q000097:blood*; D017325:Hepatitis B Vaccines / Q000276:immunology*; D006801:Humans; D017589:Immunization Programs; D007231:Infant, Newborn / Q000276:immunology*; D008297:Male; D014614:Vaccines, Synthetic / Q000276:immunology
chemical_list: D006510:Hepatitis B Antibodies; D017325:Hepatitis B Vaccines; D014614:Vaccines, Synthetic