Previous studies have shown that there are alterations in the number and affinity of interferon receptors during interferon therapy and that such alterations recover to varying degrees some time after the end of treatment. It can be conjectured that the rest period of pulsed therapy facilitates the recovery of type I interferon receptors and thus the next round of IFN therapy compared to a continuous regimen of interferon.

A large-sample, multicenter, prospective, real-world study using NAs in combination with PEG-IFN-α-2b for the treatment of CHB patients with continuous or pulsed combination therapy over a course of up to 96 weeks is proposed to compare the differences in clinical cure rates and E antigen conversion rates between groups. Multiple novel markers of hepatitis B infection, including HBV pgRNA, HBcrAg and anti-HBcAb quantification, were dynamically measured at baseline, 12, 24, 48, 72 and 96 weeks to explore the appropriate strategy for achieving clinical cure rates in CHB patients treated with NAs in combination with PEG-IFN-α-2b.

Inclusion Criteria:

1. Age 18 to 60 years, both sexes (both 18 and 60 years)
2. HBsAg positive for more than 6 months;
3. NAs treated patients on continuous NA therapy for more than 6 months with HBsAg ≥ 1500 IU/ml and HBV-DNA < 500 IU/ml at enrolment;
4. Primary treated patients with surface antigen >1500 IU, unlimited E antigen and unlimited HBV DNA at enrolment, meeting the treatment indications of the 2019 edition of the guidelines for the prevention and treatment of chronic hepatitis B.
5. negative urine or serum pregnancy test within 24 hours prior to the first dose (for women of childbearing age)

Exclusion Criteria:

1. Combined active hepatitis A, C, D, E and/or HIV infection;
2. Patients who are on future and intend to continue to use tibivudine
3. methaemoglobin greater than 100ng/ml at screening; or methaemoglobin that has not remained stable for 3 months prior to the trial and/or liver imaging suggestive of liver tumours;
4. decompensated liver disease (Child-Pugh score ≥ 7), meaning that patients will be excluded if one of the following is met: prolonged prothrombin time ≥ 3 seconds, serum bilirubin > 34umol/L, history of hepatic encephalopathy, history of oesophageal variceal bleeding, ascites;
5. pregnant or lactating women or patients with planned pregnancy during the study period and unwilling to use contraception
6. Neutrophil count < 1.5 x 10^9/L or platelet count < 90 x 10^9/L and creatinine > 1.5 ULN
7. History of severe psychiatric illness, especially depression. Major psychosis defined as major depressive disorder or psychosis, suicide attempts, hospitalisation for psychosis or incapacity for a period of time due to psychosis;
8. history of immune-mediated disease (e.g. inflammatory bowel disease, idiopathic thrombocytopenic purpura, lupus erythematosus, autoimmune haemolytic anaemia, scleroderma, severe psoriasis, rheumatoid arthritis) or abnormally elevated levels of autoimmune antibodies
9. Patients with severe combined diseases of the heart, lungs, kidneys, brain, blood and other vital organs, combined with other malignancies
10. History of severe epilepsy or current treatment with anti-epileptic drugs. Unstable control of diabetes mellitus, hypertension, thyroid disease, etc. Patients with a history of severe retinopathy or as indicated by other evidence of retinopathy;
11. History of any organ transplantation and existing functional grafts (except corneal or hair transplants);
12. Patients who are allergic to interferon and its drug components and who, in the judgment of the investigator, are unsuitable for interferon application
13. Patients who, in the opinion of the investigator, are not suitable for participation in this study.

Participants and investigators will be informed of the treatment protocol. Participants will be grouped according to the random number method at initial entry and will be given the option to continue in the current cohort or withdraw from the cohort study at their own discretion after treatment assessment at each node.