(i) Hepatitis B Vaccination Hepatitis B vaccination is the most effective way to prevent HBV infection. Hepatitis B vaccination targets are mainly newborns, followed by infants and young children and high-risk groups (e.g., medical personnel, personnel with frequent contact with blood, staff of child care institutions, organ transplant patients, people who frequently receive blood transfusion or blood products, immunocompromised people, people prone to trauma, family members of HBsAg-positive people, male homosexuals or people who have more than one sexual partner and people who are addicted to intravenous drugs, etc.). A total of 3 doses of the full vaccination are given according to the 0, 1, 6 months program, i.e., after the 1st dose of vaccine, the 2nd and 3rd doses of vaccine are given at intervals of 1 and 6 months. Newborns should be vaccinated against hepatitis B as early as possible, within 24 hours after birth. The method of vaccination is intramuscular vaccination in the anterior lateral thigh of infants and children, and intramuscular vaccination 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.The protection rate of mother-to-child transmission blocked by the hepatitis B vaccine alone is 87.8%. For newborns of HBsAg-positive mothers, 10 μg of yeast hepatitis B vaccine should be administered as early as possible within 24 h of birth. Simultaneous injection of hepatitis B immune globulin (HBIG) at different sites (preferably within 12h after birth, the dose should be ≥100IU) significantly improves the efficacy of interruption of mother-to-child transmission. It is also possible to administer 1 injection of HBIG within 12 h of birth, followed by a second injection of HBIG 1 month later, along with 10 μg of hepatitis B vaccine, and 10 μg of hepatitis B vaccine at intervals of 1 and 6 months, respectively.The latter is less convenient than the former, but it offers a higher rate of protection than the former. Newborns can be breastfed by HBsAg-positive mothers after hepatitis B vaccine and HBIG are administered within 12 h of birth. Newborns from 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 immunocompromised or non-responders, the vaccine dose and number of shots should be increased; those who do not respond to the 3-shot immunization program can receive another 3 shots, and anti-HBs in the serum should be detected 1-2 months after the second 3 shots of hepatitis B vaccine in order to determine whether antibodies are produced. The protective effect of hepatitis B vaccination for antibody responders generally lasts for at least 12 years, so the general population does not need anti-HBs monitoring or booster immunization. However, anti-HBs monitoring can be performed for high-risk groups, and booster immunization can be given if anti-HBs is <10mIU/ml. (ii) Prevention of transmission routes Safe injection (including needles for needling) should be vigorously promoted, and medical instruments such as dental instruments and endoscopes should be strictly sterilized. Medical personnel should follow the principle of standardprecautions in hospital infection management and wear gloves when contacting patients' blood, body fluids and secretions. Haircutting, shaving, pedicure, piercing and tattooing utensils in all service industries should also be strictly sterilized. Pay attention to personal hygiene, do not share razors and dental tools. Provide correct sex education. If the sexual partner is HBsAg positive, he/she should be vaccinated against Hepatitis B. Those who have more than one sexual partner should be examined regularly, strengthened management, and advised to use condom during sexual intercourse. For HBsAg-positive pregnant women, amniocentesis should be avoided, delivery time should be shortened, the integrity of the placenta should be ensured, and exposure of the newborn to maternal blood should be minimized. (III) HBV prevention after accidental exposure After accidental exposure to blood and body fluids of HBV-infected persons, the following methods can be followed: 1. Serologic testing should be done immediately for HBVDNA, HBsAg, anti-HBs, HBeAg, anti-HBe, ALT and AST, and retested in 3 and 6 months. 2.Active and passive immunization may not be specially treated if they have been vaccinated against hepatitis B and anti-HBs is known to be ≥10mIU/ml. If you have not been vaccinated against hepatitis B, or if you have been vaccinated against hepatitis B but your anti-HBs is <10mIU/ml or your anti-HBs level is unknown, you should be injected with HBIG 200~400IU immediately and be vaccinated with hepatitis B vaccine at different sites at the same time.