Evaluation of serum hepatitis B antibody level in vaccinated children after 14 years in Kashan, Iran

Hepatitis B vaccination has been conducted in neonates in the routine vaccination in Iran since 1993. This study was carried out to evaluate the serum hepatitis B antibody level in vaccinated children after 14 years in Kashan، Iran.

This prospetive cohort study was conducted on 200 fourteen-year-old children which were selected via a simple random sampling method in Kashan، Iran drung 2008-09. This subjects were have been vaccined according to the govermental guildline at 0، 2 and 6 months old. Two ml blood specimens were obtained from children and serum hepatitis B surface antibody (anti-HBs) and hepatitis B core antibody (anti-HBc) were determined by ELISA method. Immunity was interpreted as anti-HBs≥10 IU/L. Data were analyzed using SPSS-13، Chi-Square and Fisher’s exat tests.

92% girls and 95% boys، totally 187 (93. 5%) children had serum anti-HBs≥10 IU/L. Anti-HBc was positive in 3 (3%) girls and 5 (5%) boys، totally 8 (4%) which all of them had serum anti-HBS≤10 IU/L. No case of positive HBs Ag was detected. Immunity was detected in 11 of 18 (61. 1%) children with birth weight<2. 5 kg and in 176 of 182 (96. 7%) children with birth weight≥2. 5 kg (P<0. 05).

The immunity following the complete series (0، 2، 6 months old) of hepatitis B vaccination remained detectable after 14 years.