Current research status and challenges of animal models for hepatitis B

Hepatitis B virus （HBV） infection is one of the major global health problems， and it can lead to the development of liver cirrhosis and hepatocellular carcinoma. Due to the strict species specificity of HBV infection， no animal model has yet been established to fully support the complete life cycle of HBV infection and accurately reflect host immune responses and pathogenesis. Current animal models used for HBV research include various hosts such as chimpanzees， tree shrews， and mice， as well as surrogate models based on related hepatotropic viruses. Although these models have contributed significantly to the research on HBV replication， immune response， and antiviral drug evaluation， they still have certain limitations such as ethical concerns， low infection efficiency， high costs， and a lack of persistent infection. In recent years， the development of novel strategies， such as humanized mouse models with reconstituted human liver and immune systems， transgenic models， and viral vector-mediated infection systems， has greatly promoted the research on HBV biology. In the future， with the integration of emerging technologies including gene editing， tissue engineering， and multi-system reconstruction， it is possible to establish HBV infection models that can more closely mimic human pathophysiology， thereby laying a robust foundation for understanding virus-host interactions， exploring the pathways for viral clearance， and developing radical treatment strategies.