HBVn

HBVn refers to the **n-th** (or nth) generation of **Hepatitis B virus (HBV)** variants that have emerged through natural evolution and human transmission. These variants are categorized based on their genetic mutations, which can influence their behavior, transmissibility, and response to treatment. HBVn variants are studied to understand their impact on global public health, particularly in regions where hepatitis B remains endemic.

The classification of HBVn variants is primarily based on mutations in the **precore/core promoter (PC/CP) region** and the **basal core promoter (BCP)**. Common variants include those with mutations such as A1762T/G1764A, which affect viral replication and immune evasion. Some variants, such as those associated with **precore mutations (e.g., G1896A)**, may lead to reduced viral replication but can still cause chronic infection. These mutations can also contribute to drug resistance, particularly against nucleos(t)ide analogs used in antiviral therapy.

The emergence of HBVn variants is influenced by factors such as high viral loads, prolonged infection, and inadequate treatment adherence. While some variants may exhibit altered pathogenicity, most retain the ability to cause liver disease, including cirrhosis and hepatocellular carcinoma. Research into these variants is ongoing to improve diagnostic methods, treatment strategies, and vaccination approaches.

Global surveillance programs monitor HBVn variants to track their spread and assess their clinical significance. Public health initiatives continue to emphasize vaccination, early detection, and antiviral therapy to control hepatitis B transmission and mitigate the burden of chronic infection. Understanding HBVn variants is crucial for developing targeted interventions and ensuring long-term control of hepatitis B worldwide.