RESUMEN
hepatitis B [HB] virus infection represents a serious public health problem in many countries of the world, and Egypt was considered as one of the countries with a high prevalence of hepatitis B virus [HBV] infection. So the ministry of health and population conducted a mass hepatitis B vaccination program that began in 1992 to overcome this health problem. To evaluate the immune status of children born after the national HB vaccination program and to determine the relationship between the most common risk factors for HB infection and HB markers in incomplete vaccines. Three hundred children ranging in age from 12 months to 72 months were randomly recruited from 4 health offices: two from rural areas in Giza and two from urban areas in Cairo. They were tested for HB markers. The protection rate reached 98% among completely vaccinated children but it was 75.3% in incompletely vaccinated children [p< 0.001]. The infection rate was 4% among complete vaccines while it reached 6.3% among incomplete vaccines. Two percent of the completely vaccinated children and 6% of tile incomplete vaccines were carriers to HBV. This study indicates the efficacy of HBV vaccination. But to achieve maximum protection it is important to adhere to the complete vaccination schedule. A booster dose of HB vaccine is not needed six years after complete vaccination