1. Individuals receiving vaccine protection have low immune response capacity and cannot produce protective antibodies. The absence or weak immune response after hepatitis B vaccination is related to many factors, such as old age, obesity, smoking, alcoholism, immune deficiency, immune tolerance or the presence of certain chronic diseases such as combined giant cell infection, etc. In addition, it may also be related to genetic factors – human leukocyte antigen. 2.Injected vaccine dose is not enough to produce protective antibodies, then the vaccine dose can be increased appropriately under the guidance of physicians. 3, the infant is infected in utero, the mother infected with hepatitis B virus, the blood of her newborn already contains hepatitis B virus particles, and the vaccination has no protective effect. 4.The infected virus is a mutant virus (which cannot be detected by the existing two-and-a-half reagents), and the hepatitis B e antigen (HBeAg) or HBV-DNA should be further examined to confirm the diagnosis. 5. People with deficient or low immune function do not easily produce antibodies. Injection of hepatitis B vaccine requires higher dose.