الفهرس 
Hepatitis B virusOnly 14 pages are availabe for public view
 |  | from | 151 |  |  |
| | | from | 151 | | |
Abstract
HBV vaccine is now one of the most widely used vaccines in the world and is part of the routine vaccination schedule for many of the world’s infants and children. It is the world’s first cancer prevention vaccine and the first vaccine to prevent a sexually transmitted disease. Thus the present study designed to determine the efficacy of HBV vaccine in eliciting protective immunity against HBV infection in children and adult health care workers. To asses the duration of protective immunity after 3 doses regimen of HBV vaccine and a trial to determine the optimal policy of booster vaccination. This study was conducted on 54 Vaccinated adult HCWs, 15 unvaccinated adult HCWs as control group, their ages ranged from (24-57) years and 64 Children below 14 years. Each group has been classified according to time passed since the last vaccine dose into three sub groups; vaccinated less than 5 years, vaccinated from 5 to 10 years and vaccinated since more than 10 years. All included groups were subjected to thorough History taking and full clinical examination followed by a series of investigation including anti-HBs titer. According to the results of anti-HBs, the included groups were sub-divided into seropositive (Anti-HBs titer ≥10 IU/L) and seronegative subjects (Anti-HBs titer < 10 IU/L). Then the seronegative subjects have been given a booster dose of HBV vaccine with re evaluation of anti-HBs titer after one month. The results of our study proved that: HBV vaccine is protective against HBV infection. The longer the time lapsed after vaccination, the lower the seroprotection rate and the lower mean anti-HBs. There is an anamnestic response to booster vaccination, even in subjects who had lost anti-HBs antibody that confirms the persistence of an effective immunological memory in vaccinees. There is a high positive correlation between anti-HBs titer before and after booster dose in seronegative subjects. There is a significant difference between the anti-HBs titer in diabetic and non diabetic children before the booster dose, but no statistically significant difference after the booster dose. There is no significant difference between the initial anti-HBs titer, anti-HBs titer after booster dose and degree of seroconversion between subjects with or without HCV. A booster dose is probably not mandatory even after more than 10 years following HBV vaccination in healthy subjects, however, it should be considered in especial groups.