Randomly selected 200 subjects were tested for quantitative hepatitis B surface antibody (HBsAb) estimation in a remote tribal area of Arunachal Pradesh, India to measure the protective immunity after vaccination in the backdrop of hyperendemic HBV infection. About 64.6 and 40.0% had HBsAb above 10 mIU/ml in the vaccinated and unvaccinated subjects, respectively (p=0.002, OR: 2.7, 95% CI: 1.5-5.0). Universal vaccination across all age group may be more effective as 63.3% in the unvaccinated group above 15 years did not have protective level of antibody against HBV infection in our study.