What is the primary component of the Hepatitis B vaccine?

The primary component of the Hepatitis B vaccine is the Hepatitis B surface antigen (HBsAg). This vaccine is made from recombinant DNA technology, which produces the HBsAg protein that is non-infectious and cannot cause disease. When administered, this antigen stimulates the immune system to produce antibodies against the Hepatitis B virus, thus providing protection against future infections.

By inducing an immune response without the risk of actual infection, the vaccine allows for the establishment of immunological memory, equipping the body to effectively combat the virus if encountered later. This mechanism is key to preventing Hepatitis B virus-related diseases, such as acute hepatitis, chronic liver disease, and hepatocellular carcinoma.

Other components, such as the core antigen and e antigen, play different roles in the life cycle of the virus or in the infection process but are not used in the vaccine itself. The vaccine's focus is solely on the surface antigen, which is crucial for conferring immunity.