1Department of Immunology, School of Public Health, Tehran University of Medical Sciences, Tehran
2Department of Immunology, School of Medicine, Rafsanjan University of Medical Sciences, Rafsanjan
3Kerman Health Center, Kerman University of Medical Sciences, Kerman
4Health Research Center of Urmia, Institute of Public Health Research, Tehran University of Medical Sciences, Tehran, Iran
Objective: To compare immunogenicity of a recombinant hepatitis B (HB) vaccine in two groups of neonates born in two cities of Iran with different geographic and ethnic backgrounds. Materials and Methods: Ten micrograms of a recombinant HB vaccine was administered under field condition to Iranian healthy neonates at 0, 1.5 and 9 months intervals. The subjects consisted of two groups of 290 and 231 neonates selected from two cities located at north-west (Urmia) and south-east (Kerman) of Iran, respectively. The level of anti-HBs antibody was quantitated in serum 2-4 weeks after administration of the last vaccine dose, by sandwich ELISA. Results: A higher seroprotection rate (anti-HBs> 10 IU/L) (98.3% vs. 96.1%) and significantly increased serum anti- HBs antibody titer (11869 vs. 6104 IU/L) (P<0.001) were induced in vaccinated neonates from Urmia city, compared to those born in Kerman. Conclusion: These findings suggest contribution of ethnic and/or environmental factors in the antibody response to recombinant HB vaccine in human.