Chronic viral hepatitis B generally has an incubation period, which mostly ranges from about six weeks to six months, with an average of about three months. The period between the invasion of the hepatitis virus into the human body and the appearance of clinical symptoms is also clinically known as the incubation period. During the incubation period, patients may be negative for Hepatitis B surface antigen, and it is recommended that patients have their blood tested again at three months and six months to see if the Hepatitis B surface antigen is positive. Because hepatitis B virus is not easy to treat, so for normal people, it is recommended that normal vaccination against hepatitis B. Generally, after hepatitis B vaccination, after about 1-3 weeks, normal human body will establish immune defense mechanism through immune response, and have immunity against hepatitis B virus. It is recommended that patients check the hepatitis B system one week or one month after hepatitis B vaccination to see what the titer of hepatitis B surface antibody is, and if the titer is higher, the chance of hepatitis B virus infection is also smaller.