1.Hepatitis B vaccine prevention Hepatitis B vaccination is the most effective way to prevent hepatitis B infection. In 1992, the Ministry of Health of China included hepatitis B vaccine into the management of planned immunization, and all newborns were vaccinated with hepatitis B vaccine, but the vaccine and its vaccination cost had to be paid by parents. Hepatitis B vaccination is mainly given to newborns, followed by infants and children and high-risk groups (e.g. medical personnel, people who are frequently exposed to blood, workers in childcare institutions, organ transplant patients, frequent recipients of blood transfusions or blood products, people with low immune function, people prone to trauma, family members of HBsAg-positive people, men who are gay or have multiple sexual partners, and people who inject drugs intravenously). Hepatitis B vaccine is administered in 3 doses, according to the 0, 1 and 6 months procedure, i.e. after the first vaccination, the second and third doses are administered at 1 and 6 months intervals. Hepatitis B vaccination for newborns is given as early as possible, within 24 hours of birth. The site of vaccination is intramuscular in the lateral anterior thigh for newborns and intramuscular in the middle deltoid muscle of the upper arm for children and adults. The protection rate for blocking mother-to-child transmission with hepatitis B vaccine alone is 87.8%. For newborns of HBsAg-positive mothers, hepatitis B immunoglobulin (HBIG) should be administered as early as possible within 24 h of birth, preferably within 12 h of birth, at a dose of ≥100 IU, along with 10 μg of recombinant yeast or 20 μg of Chinese hamster oocyte (CHO) hepatitis B vaccine at different sites to significantly improve the efficacy of blocking mother-to-child transmission. Alternatively, one dose of HBIG can be administered within 12 h of birth, followed by a second dose of HBIG 1 month later, and one dose of 10 μg recombinant yeast or 20 μg CHO hepatitis B vaccine at different sites, followed by a second and third dose of hepatitis B vaccine (10 μg recombinant yeast or 20 μg CHO hepatitis B vaccine each) at 1 and 6 months intervals, respectively. 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 HBIG and hepatitis B vaccine are administered within 12 h of birth. Newborns of HBsAg-negative mothers can be immunized with 5 μg recombinant yeast or 10 μg CHO hepatitis B vaccine; children who were not vaccinated against hepatitis B during the neonatal period should be given a catch-up dose of 5 μg recombinant yeast or 10 μg CHO hepatitis B vaccine; 20 μg recombinant yeast or 20 μg CHO hepatitis B vaccine is recommended for adults. For those who are immunocompromised or non-responders, the vaccination dose and number of doses should be increased; for those who do not respond to the 3-dose immunization program, 3 more doses can be administered, and the anti-HBs in the serum should be tested 1~2 months after the second 3-dose hepatitis B vaccination. The protective effect of hepatitis B vaccination for those who have antibody response generally lasts at least 12 years, therefore, the general population does not need anti-HBs monitoring or Therefore, the general population does not need anti-HBs monitoring or booster immunization. However, anti-HBs monitoring can be conducted for high-risk groups, and if anti-HBs is < 10 mIU/ml, booster immunization can be given. 2. 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 disinfected. Medical personnel should wear gloves when touching patients' blood, body fluids and secretions in accordance with the principle of standard prevention in hospital infection management to strictly prevent medical transmission. Tools for haircutting, shaving, pedicure, piercing and tattooing in the service industry should also be strictly disinfected. Pay attention to personal hygiene, do not share razors and dental tools and other supplies. Provide proper sex education, and if the sexual partner is HBsAg positive, hepatitis B vaccination should be given; for those who have multiple sexual partners, regular checkups should be conducted to strengthen management, and condoms should be used during sexual intercourse. For HBsAg-positive pregnant women, amniocentesis should be avoided and the delivery time should be shortened to ensure the integrity of the placenta and minimize the chance of exposing the newborn to maternal blood. 3.Prophylaxis after accidental exposure to hepatitis B After accidental exposure to blood and body fluids of hepatitis B infected persons, the following methods can be followed: (1) Serological testing HBsAg, anti-HBs, ALT, etc. should be tested immediately and retested within 3 and 6 months. (2) Active and passive immunization If hepatitis B vaccination has been given and anti-HBs ≥10 mIU/ml is known, no special treatment may be given. If you have not received hepatitis B vaccine, or have received hepatitis B vaccine but anti-HBs <10 mIU/ml or the level of anti-HBs is unknown, you should immediately inject HBIG 200~400 IU and receive one dose of hepatitis B vaccine (20mg) at different sites at the same time, and receive the second and third doses of hepatitis B vaccine (20mg each) after 1 and 6 months, respectively. 4. Management of patients and carriers When diagnosing patients with acute or chronic hepatitis B, medical personnel at all levels should promptly report to the local Center for Disease Control and Prevention (CDC) in accordance with the Law of the People's Republic of China on the Prevention and Control of Infectious Diseases, and should indicate whether it is acute or chronic hepatitis B. It is recommended that family members and other close contacts of patients be tested for serum HBsAg, anti-HBc and anti-HBs, and that susceptible individuals (those negative for all three markers) be vaccinated against hepatitis B. Patients with acute or chronic hepatitis B may be hospitalized or treated at home depending on their condition. Medical devices and instruments used by patients (e.g. blood collection needles, acupuncture needles, surgical instruments, scratch needles, probes, endoscopes and dental drills, etc.) should be strictly disinfected, especially for contaminants with blood. Chronic hepatitis B carriers and HBsAg carriers can live, study and work as usual, except for those who cannot donate blood and those who cannot perform special occupations (such as military service) according to national laws, but follow-up visits should be strengthened. The infectivity of hepatitis B patients and carriers depends mainly on the level of hepatitis B DNA in the blood, but not on serum ALT, AST or bilirubin levels.