Seroconversion after Recombinant Hepatitis B Vaccination

Background: Hepatitis B virus infection is an important public health problem with significant morbidity andmortality. Recombinant hepatitis B vaccine for the prevention of hepatitis B virus infection is in practice in differentparts of the world since its availability in 1986. Government of Bangladesh has also included hepatitis B vaccine inEPI schedule since 2005.Materials and methods: This study was carried out to assess the seroconversion status among hepatitis Bvaccinated individuals. A total of 190 individuals including 150 vaccinated persons and 40 non-vaccinated apparentlyhealthy individuals were included as study population. Sources of vaccinated persons were from both EPI and non-EPI schedule of vaccination. Age and sex matched non-vaccinated individuals served as controls for the study. Allindividuals constituting the study population were screened for HBsAg by Immunochromatographic strip test andonly HBsAg-negative persons were included for estimation of their anti-HBs titer.Results: Out of 150 vaccinated individuals, 133(88.67%) were found to have anti-HBs titer in the protective level(>10 IU/L), while 17(11.33%) individuals had anti-HBs titer below the protective level (<10 IU/L). All non-vaccinatedcontrols had anti-HBs titers below the protective level. Regarding immune response developed among vaccinatedindividuals, 67.78%, 23.33% and 8.89% were good-responders, hypo-responders and non-responders respectively.Mean titer of anti-HBs was found significantly higher among recipients who received booster dose than those whoreceived 3 doses schedule (863.39 IU/L vs. 262.40 IU/L), indicating high antibody titer develops after booster dose.Vaccinated group included 85 (56.67%) men and 65 (43.33%) women with protective level of anti-HBs titer foundin 85.88% male and 92.31% female individuals. There was no significant difference of anti-HBs titer between maleand female (p>0.05). Vaccinated individuals from lower socioeconomic condition have had comparatively low rateof protective antibody than people from middle and upper classes.Conclusion: Recombinant HB vaccine induces good level of protective immunity among vaccinated persons.Keywords: Hepatitis B; hepatitis B vaccine; seroconversion; BangladeshDOI: 10.3329/jom.v11i2.5461J MEDICINE 2010; 11 : 143-150