Hepatitis B Vaccine (Recombinant)

Hepatitis B Vaccine is an ingredient in the EMA-withdrawn product Quintanrix. It is marketed in Canada as Engerix B. It is also a part of Twinrix (Hep A/Hep B vaccine) available also in Canada.
The hepatitis B virus induces a severe form of viral hepatitis. Other causative agents are hepatitis A virus, and the non-A, non-B hepatitis viruses. Hepatitis D virus, a defective virus requiring the “keeper function” of the hepatitis B virus, occurs either as a co-infection or super-infection in a HBsAg carrier.

Transmission of the virus occurs through percutaneous contact with contaminated blood, serum or plasma. Infection may also occur by the exposure of mucous surfaces, or intact or damaged skin to other body fluids such as saliva, mucosal secretions and semen.

There is no specific treatment for hepatitis. The incubation period may be as long as 6 months, followed by a very complex clinical course of an acute or chronic nature, often leading to hospitalization.

Viral hepatitis caused by hepatitis B virus is a major worldwide health problem, though the incidence and epidemiology vary widely among geographical areas and population subgroups.

In Canada, the United States and Northern Europe, 4% to 6% of the population are infected during their lifetime (mostly young adults); between 5% and 10% of infections lead to persistent viremia (carrier state). Certain population subgroups in these areas, however, are at high risk (see Indications and Clinical Use).

In Asia, infection often occurs early in life, leading to a hepatitis B marker prevalence of more than 70% in the general population and a carrier rate of up to 20%.

It is estimated that the reservoir of persistent hepatitis B surface antigen carriers amounts to 350 million people worldwide. Carriers are at a high risk of developing chronic liver disease which may lead to cirrhosis or primary hepatocellular carcinoma. A significant reduction in the incidence of hepatocellular carcinoma has been observed in children aged 6 to14 years following a nationwide hepatitis B vaccination in Taiwan. This resulted from a significant decline in the prevalence of hepatitis B antigen, the persistence of which is an essential factor in the development of hepatocellular carcinoma.

Vaccination against hepatitis B is expected in the long term to reduce the overall incidence of both hepatitis B and the chronic complications such as chronic active hepatitis and cirrhosis.