In order to standardize the prevention, diagnosis and treatment of chronic hepatitis B, the Chinese Medical Association Branch of Hepatology and the Infectious Diseases Branch organized domestic experts to develop the Guidelines for the Prevention and Treatment of Chronic Hepatitis B in 2005 [1]. In the past 5 years, basic and clinical research on chronic hepatitis B has made great progress at home and abroad, so we update this guideline. These guidelines are intended to help physicians make rational decisions in the diagnosis and prevention of chronic hepatitis B, but are not mandatory standards and cannot include or address all issues in the diagnosis and treatment of chronic hepatitis B. Therefore, when faced with a particular patient, clinicians should develop a comprehensive and reasonable treatment plan based on their professional knowledge, clinical experience and available medical resources, with full knowledge of the best clinical evidence about the disease and careful consideration of the patient’s specific condition and his or her wishes. We will continue to update and improve this guideline in accordance with the relevant progress at home and abroad. I. Pathogenesis After HBV invades hepatocytes, part of the double-stranded cyclic HBVDNA is used in the nucleus to extend the positive chain with negative-stranded DNA as a template to repair the gap region in the positive chain, forming covalent closed-loop DNA (cccDNA); then cccDNA is used as a template to transcribe into several mRNAs of different lengths, which are used as pregenomic RNA and encode various antigens of HBV. The cccDNA has a long half-life (decay) and is difficult to completely remove from the body. HBV has been found to have 9 genotypes from A to I [4,5], with types C and B predominating in China. HBV genotype is associated with disease progression and the effect of interferon alpha therapy. Compared with those infected with genotype C, those infected with genotype B show HBeAg serological conversion earlier and progress less frequently to chronic hepatitis, cirrhosis and primary hepatocellular carcinoma. II. epidemiology Only 0.96% [15,16]. According to this projection, the existing chronic HBV infection in China is about 93 million people, including about 20 million cases of chronic hepatitis B [17]. HBV is a blood-borne disease and is mainly transmitted via blood (e.g., unsafe injections, etc.), mother-to-child and sexual contact [14]. Due to the implementation of strict HBsAg screening for blood donors, HBV infection caused by blood transfusion or blood products has been less frequent; transmission through broken skin and mucous membranes is mainly due to the use of medical devices that are not strictly sterilized, invasive diagnostic and surgical operations, unsafe injections, especially drug injections; others such as pedicure, tattoo, earring piercing, accidental exposure of medical personnel at work, sharing razors and toothbrushes Other infections, such as foot massage, tattooing, earring piercing, accidental exposure of medical personnel at work, sharing of razors and toothbrushes, can also be transmitted (III). Mother-to-child transmission occurs mainly during the perinatal (labor and delivery) period, mostly from exposure to the blood and body fluids of HBV-positive mothers during delivery, and has been greatly reduced with the use of hepatitis B vaccine combined with hepatitis B immunoglobulin [18]. The risk of HBV infection is increased by unprotected sexual contact with HBV-positive individuals, especially those with multiple sexual partners. HBV is not transmitted through the respiratory and digestive tracts, so daily study, work or living contacts, such as working in the same office (including sharing office supplies such as computers), shaking hands, hugging, living in the same dormitory, eating in the same restaurant and sharing toilets without blood exposure, generally do not transmit HBV. epidemiological and experimental studies have not found that HBV can be transmitted by blood-sucking insects (mosquitoes, bedbugs, etc.) [19 The epidemiological and experimental studies have not found that HBV can be transmitted by blood-sucking insects (mosquitoes, bedbugs, etc.) [19]. Third, the natural history of patients at this stage can return to the HBeAg-positive state (especially in the immunosuppressed state such as when receiving chemotherapy). Not all people infected with HBV go through the above four stages. Only a minority (about 5%) of HBV infections in the neonatal period result in spontaneous clearance of HBV, while most have a long period of immune resistance and then enter the immune clearance phase. However, most HBV infections in adolescence and adulthood do not have an immune tolerance period but enter directly into the immune clearance phase, and most of them can clear HBV spontaneously (about 90%-95%), while a minority (about 5%-10%) develop HBeAg-positive chronic hepatitis B. Spontaneous HBeAg serologic conversion occurs mainly during the immune clearance phase, with an annual incidence of about 2%-15%, with a higher incidence in those younger than 40 years of age, with elevated ALT, and with infection with HBV genotypes A and B. HBsAg clearance occurs in about 0.5%-1.0% per year after HBeAg serologic conversion [25]. The incidence of cirrhosis in patients with chronic HBV infection is related to the infection status. Patients in the immune tolerance phase have only very mild or no progression of liver fibrosis, whereas the immune clearance phase is a period of high incidence of cirrhosis. The cumulative incidence of cirrhosis is positively correlated with persistently high viral load, and HBVDNA is a risk factor that can independently predict the development of cirrhosis independently of HBeAg and ALT. Risk factors for the development of cirrhosis also include alcoholism. Prevention (a) Hepatitis B vaccine prevention Hepatitis B vaccination is the most effective way to prevent HBV infection. The targets of hepatitis B vaccination are mainly newborns [37], followed by infants and young children, unimmunized people under 15 years of age and high-risk groups (e.g., medical personnel, people with frequent exposure to blood, staff of childcare institutions, organ transplant patients, frequent recipients of blood transfusions or blood products, immunocompromised people, people prone to trauma, family members of HBsAg-positive people, men who are gay or have multiple The hepatitis B vaccine should be administered to all patients (including those who have multiple sexual partners and those who inject drugs intravenously). Three doses of hepatitis B vaccine are required for the whole course, according to the 0, 1 and 6 months procedure, i.e., after the first vaccination, the second and third doses are given at intervals of 1 month and 6 months. Hepatitis B vaccination for newborns should be given within 24 hours after birth, the earlier the better. The vaccination site is intramuscular in the lateral anterior gluteal muscle for newborns and intramuscular in the middle deltoid muscle of the upper arm for children and adults. Newborns of HBsAg-negative mothers can be immunized with 5 μg or 10 μg yeast or 10 μg CHO hepatitis B vaccine; children who were not vaccinated with hepatitis B vaccine during the neonatal period should be given a catch-up dose of 5 μg or 10 μg recombinant yeast or 10 μg CHO hepatitis B vaccine; for adults, 20 μg yeast or 20 μg CHO hepatitis B vaccine is recommended. For those who are immunocompromised or non-responders, the vaccination dose (e.g. 60 μg) and number of doses should be increased; for those who do not respond to the 3-dose immunization program, they can receive 3 more doses and have their serum tested for anti-HBs 1~2 months after the second 3-dose hepatitis B vaccine, and if they still do not respond, they can receive a 60 μg recombinant yeast hepatitis B vaccine.