Hepatitis B virus has three antigenic components: surface antigen (HBsAg), core antigen (HBcAg) and e antigen (HBeAg). These three antigens in the body can cause the body’s immune response, producing the corresponding three antibodies, namely: anti-HBs, anti-HBc and anti-HBe. These antigens and antibodies can be used as diagnostic markers of hepatitis B virus infection. However, since it is difficult to detect the core antigen of hepatitis B virus (HBcAg) in the serum by general methods, only five indicators of HBsAg and anti-HBs, HBeAg and anti-HBe, anti-HBc can be detected. It is also commonly known as hepatitis B five or hepatitis B two to half. The reproduction of the hepatitis B virus is what we often call “replication” of the virus. This process takes place in the liver cells. After the hepatitis B virus infects the liver cells, it uses the energy and substances in the liver cells to replicate each part of the virus and then assembles it. One characteristic of its replication process is that it produces an excessive amount of viral outer membrane (HBsAg). Therefore, we say that it is a virus that loves to make “clothes”. In the serum of hepatitis B virus-infected patients, the virus particles can be as high as 1013 copies/ml, of which only one ten thousandth of the intact hepatitis B virus particles, only a few are complete with full genes and infectious virus particles. Therefore, in some patients, only the surface antigen of the hepatitis B virus can be detected in the serum, while the e antigen and viral DNA are negative. The surface antigen of hepatitis B virus stimulates the body to produce surface antibodies – anti-HBs are “neutralizing antibodies” that can “neutralize” and remove hepatitis B virus, which is the main weapon of the body’s immune function to defeat hepatitis B virus. The hepatitis B vaccine can be produced by using a piece of the hepatitis B virus surface antigen structure as the antigen, and the hepatitis B vaccine can prevent human infection with the hepatitis B virus. Hepatitis B virus core antigen and e antigen have a role in promoting viral maturation and often indicate the presence of intact viral particles in the body, which are infectious. At the same time, e antigen is a “by-product” of the hepatitis B virus replication process. Therefore, the presence of e antigen in the serum is also a sign of viral replication. In these five indicators, if HBsAg, HBeAg and anti-HBc three indicators are positive, is often said to be the hepatitis B “big three positive” infection; if HBsAg, anti-HBe and anti-HBc three indicators are positive, is often said to be the hepatitis B “small three positive The “small three positive” infected person. I hope that through my description, you can read your own laboratory test and understand your own disease.