Hepatitis B vaccination is the most effective way to prevent HBV infection. The targets of hepatitis B vaccination are mainly newborns, followed by infants and high-risk groups (e.g. medical personnel, people who have frequent contact with blood, workers in childcare institutions, organ transplant patients, people who frequently receive blood transfusions or blood products, people with low immune function, people who are prone to trauma, family members of HBsAg-positive people, gay men or people with multiple sexual partners and intravenous drug addicts, etc.). A total of 3 doses of vaccine will be administered, according to the 0, 1 and 6 months procedure, i.e. after the first dose of vaccine, the second and third doses will be administered at 1 and 6 months intervals. Hepatitis B vaccination for newborns is given as early as possible, within 24 hours after birth. Vaccination is given intramuscularly in the anterior lateral thigh for infants, and intramuscularly in the middle deltoid muscle of the upper arm for children and adults. The dose of recombinant yeast hepatitis B vaccine is 5 μg or 10 μg for newborns and children, and 10 μg or 20 μg for adults; the dose of recombinant Chinese hamster oocyte (CHO) hepatitis B vaccine is 10 μg for newborns and children, and 20 μg for adults. 87.8% protection rate for blocking mother-to-child transmission with hepatitis B vaccine alone. For newborns of HBsAg-positive mothers, 10 μg of yeast hepatitis B vaccine should be administered as early as possible within 24 h after birth, along with hepatitis B immunoglobulin (HBIG, preferably within 12 h after birth, at a dose of ≥100 IU) at different sites, to significantly improve the effectiveness of blocking mother-to-child transmission. The latter is less convenient than the former, but its protection rate is higher than the former. Newborns can receive breastfeeding from HBsAg-positive mothers after receiving hepatitis B vaccine and HBIG within 12 h of birth. Newborns of HBsAg-negative mothers can be immunized with 5 μg of yeast hepatitis B vaccine; 20 μg of yeast hepatitis B vaccine is recommended for adults. For those who are immunocompromised or have no response to immunization, the vaccination dose and number of doses should be increased; those who do not respond to the 3-dose immunization program can receive 3 more doses, and the anti-HBs in the serum should be tested 1 to 2 months after the second 3-dose hepatitis B vaccination to determine whether antibodies are produced. The protective effect of hepatitis B vaccination for those with antibody response generally lasts for at least 12 years, so there is no need for anti-HBs monitoring or booster immunization for the general population. However, anti-HBs monitoring can be conducted for high-risk groups, and if anti-HBs < 10 mIU/ml, booster immunization can be given. Safe injection (including needles for needling) should be promoted and medical instruments such as dental instruments and endoscopes should be strictly disinfected. Medical personnel should wear gloves when touching patients' blood, body fluids and secretions according to the principle of standard precautions in hospital infection management. Haircuts, shaves, pedicures, piercings and tattoos in all service industries should also be strictly disinfected. Pay attention to personal hygiene, do not share razors and dental tools, etc. Provide proper sex education, and if the sexual partner is HBsAg positive, hepatitis B vaccination should be given; those who have multiple sexual partners should be checked regularly, strengthen management, and be advised to use condoms during sexual intercourse. For HBsAg-positive pregnant women, they should avoid amniocentesis, shorten the delivery time, ensure the integrity of the placenta, and minimize the chance of exposing the newborn to maternal blood. III. HBV prophylaxis after accidental exposure After accidental exposure to blood and body fluids of HBV-infected persons, the following methods can be followed: 1. Serological testing HBV DNA, HBsAg, anti-HBs, HBeAg, anti-HBe, ALT and AST should be tested immediately and retested within 3 and 6 months. 2. Active and passive immunization If you have received hepatitis B vaccine and have known anti-HBs ≥ 10 mIU/ml, you may not have special treatment. If you have not received hepatitis B vaccine, or if you have received hepatitis B vaccine but the anti-HBs < 10 mIU/ml or the level of anti-HBs is unknown, you should immediately inject HBIG 200-400 IU and receive hepatitis B vaccine at different sites at the same time.