Background of Study
Hepatitis B is a disease caused by hepatitis B virus (HBV) which infects the liver of hominoidae, including human, and cause an inflammation of the liver called hepatitis. The disease was originally known as "serum hepatitis" that caused epidemics in parts of Asia and Africa, and it is endemic in China. About a one third of the world's population or more than 2 billion people have been infected with the hepatitis B virus. This includes 350 million chronic carriers of the virus. Transmission of hepatitis B virus results from exposure to infectious blood or body fluids (Bryant, 1992)
Hepatitis B is also a potentially life-threatening liver infection which it is cause by hepatitis B virus and it is one of the major global health problems and it is the most serious type of hepatitis infection. Hepatitis can lead to chronic liver disease and somehow puts the people at a high risk of liver cirrhosis leading to liver cancer which can caused us even to death. Liver disease activity and prognosis have been reported to be generally more serious in the presence of double infection; although an inverse relationship in the replicative levels of the two agents has been noted, suggesting viral interference, particularly in cases of
chronic hepatitis. Thus, the two viruses seem to inhibit each other at the molecular level, while cytopathic effects appear to be enhanced.
The Hepatitis B vaccine is developed for the prevention of hepatitis B surface antigen (HBsAg). A course of three (3) vaccine injections are enough to prevent the infections if a person would response to the therapy. The vaccine is given after the person found to be negative which means the immune system is yet expose to the virus. The first dose about 15 ml will be injected on the first month followed by the second dose on the following month and third dose is given one month after the second dose. A booster dose is however recommended one year after the third dose. That is to boost the immunity of the person for life long immunity. Afterward the immune system will established an antibody to counter the Hepatitis B virus surface antigen when infection would arise thus protects the person from harm. This antibody and immune system memory then provide immunity to hepatitis B infection. The first vaccine became available in 1981.
Many new types of vaccine are currently under investigation, including those with yeast using synthetic protein and other recombinant DNA techniques. The goal of...