ABSTRACT
Hepatitis B is a disseminated liver inflammation from HBV, that causes diseases and a large number of deaths. Regarding the fact that some of the vaccinated people are non responder [NR], evaluation of immunity in vaccinated one and identification of NR especially in high risk group in necessary. In this descriptive study blood samples of all medical Students of Borujerd Azad University at the age of 18-25 and vaccinated personnel of Borujerd Shariaty hospital were tested for Anti. HBS-Ab level by ELISA method with Radim kit [cat.KHB31]. Results were analyzed according to the number of received vaccines, the duration of vaccination and demographic criteria using descriptive statistics. About 90% of samples had protective immunity and 10% were NR. 8% of immune group had more than 1000, 17.2% between 500-1000 and and 74.8% between 10-500 miu/ml of Ab titer. About 75% of immune samples had received two vaccines. In NR group 53% had received three vaccines and 47% had two. 4% of samples were immune with the duration less than one months after vaccination which 85% of them had two vaccines. Herd immunity was 90% which is accordant to most studies. In some studies with different results the effective criteria were not differentiated. So regarding these differences, vaccinated people are recommended to evaluate their HBS. Ab level