RESUMO
Hepatitis B infection is still a major global health problem even though safe and effective vaccines have been available for more than 30 years. Although development of protective antibody to hepatitis B surface antigen (anti-HBs) is a common phenomenon after vaccination as well as natural infection, sometimes it does not appear even after complete vaccination. In the present study, whether the impairment of the development of anti-HBs in naturally infected and/or vaccinated populations is associated with immunomodulating risk factors (i.e., age, gender, smoking, and diabetes) and/or other risk factors (i.e., socioeconomic status, dental, and saloon exposure) was investigated through a cross-sectional study. Among 204 nonvaccinated patients, 132 (64.7%) tested positive for anti-HBc, indicating that they had been exposed to hepatitis B virus (HBV) at least once in their lifetime. Exposure to HBV (anti-HBc positive) was significantly higher among low-income people, dental exposed, and saloon users. Among anti-HBc positive patients, only 44 (33.3%) developed natural immunity with anti-HBs. Impairment in anti-HBs formation was found to be significantly high among cigarette smokers. However, no significant association of anti-HBs development was observed with age, gender, socioeconomic status, diabetes, dental exposure, and using saloon. Consistently, the frequency of developing protective anti-HBs (≥10 IU/L) among a vaccinated population was almost nine times less among smokers. These data suggest that anti-HBs development, either naturally or after vaccination, is significantly lower among smokers. It emphasizes the need to check the anti-HBs status in smokers after vaccination, and a booster vaccination should be administered if the anti-HBs antibody titer decreases below the protective level.