The distribution of chronic hepatitis B viral (HBV) infection varies widely across the globe, from regions high to intermediate, to low endemicity. Clinical manifestations of chronic HBV infection range from no signs or symptoms of disease (the majority of patients) to the warning signs of end‐stage liver disease. Hepatitis B vaccination is highly effective in preventing hepatitis B and is cost effective. In the current era of highly active antiretroviral therapy (HAART), among persons with HIV/AIDS, advanced liver disease associated with chronic viral hepatitis is now the leading cause of death. Interferons, which have antiviral, antiproliferative, and immunomodulatory properties, are often involved in the host's control or elimination of acute and chronic viral infections. Patients with chronic HBV infection undergoing cytotoxic chemotherapy or other therapies that perturb immunological competence are at risk of disease reactivation that can be severe and even life‐threatening.