Transmission: 1, blood transmission: blood transmission is one of the most common ways of transmission of hepatitis B, such as being infected during blood transfusion, but with the progress of medicine, this phenomenon has been effectively controlled, but not yet eradicated. 2, medically transmitted: medically transmitted means infected in the process of medical treatment, most of which currently exists is the infection caused by micro-injections or vaccinations, so pay special attention to injections, vaccinations, tattoos and other medical instruments used. 3, mother-to-child transmission: acute hepatitis B or mothers carrying hepatitis B surface antigen can pass the hepatitis B virus to their newborns, especially mothers carrying hepatitis B surface antigen as the main type of infection. (It is worth mentioning that hepatitis B immunoglobulin can effectively inhibit the transmission of hepatitis B from mother to child or from father to child, with an efficiency rate of more than ninety percent.) 4, sexual transmission: sexual transmission of hepatitis B virus is an important way of infection of sexual partners, this transmission also includes the transmission between family couples. Prevention: The most effective preventive measure for mother-to-child transmission of HBV is the vaccination of newborns against hepatitis B, which induces the body to actively produce anti-HBs and play an anti-HBV role. The body is immune to HBV 35-40 d after the start of hepatitis B vaccination; the third dose of vaccination can cause a significant increase in anti-HBs levels. The rate of positive anti-HBs conversion in newborns after full vaccination against hepatitis B is as high as 95%-100%, and the protection period can exceed 22 years. The human body has immune memory after actively producing anti-HBs, and even after anti-HBs turn negative, the body can produce anti-HBs in a short time when exposed to HBV again, so there is no need for booster vaccination for non-high-risk people.