Hepatitis B can be contracted by kissing, because hepatitis B is transmitted through blood and body fluids, saliva is one of the body fluids, so it can be transmitted through saliva, saliva, sweat, semen, vaginal secretions and breast milk, and other body fluids contain hepatitis B virus, so close living and sexual contact can infect hepatitis B. In order to avoid hepatitis B infection, vaccination against hepatitis B is the main measure that can help to avoid being infected by hepatitis B patients. After a person is vaccinated against hepatitis B, he can produce hepatitis B surface antibodies, and the protective antibodies can help avoid being infected by hepatitis B patients, especially for newly born babies, if the mother is a hepatitis B patient, the hepatitis B vaccine and hepatitis B immunoglobulin can be given immediately after birth, and the protection rate can reach more than 95%.