Hepatitis B virus (HBV) infection remains a major global public health problem and is a leading cause of chronic liver disease, cirrhosis, and hepatocellular carcinoma. Although universal childhood vaccination has significantly reduced HBV prevalence worldwide, vaccination coverage among adults remains inadequate, particularly in low- and middle-income countries. This gap continues to sustain viral transmission and hinders global elimination efforts. The aim of this study was to assess the organization of hepatitis B vaccination programs among adults, identify barriers to immunization, and evaluate factors influencing vaccine coverage, with a focus on the Kyrgyz Republic. A structured literature review was conducted using international databases, including PubMed, Scopus, and Web of Science, along with relevant national sources. The review examined HBV epidemiology, vaccine effectiveness, and challenges related to adult immunization. The findings show that although initial vaccination uptake among adults is relatively high, completion of the full three-dose schedule is often low, with noticeable drop-off between doses. Significant regional differences in coverage were identified, mainly due to disparities in healthcare access, service organization, and population mobility. Key barriers include limited awareness, vaccine hesitancy, and financial and logistical constraints within healthcare systems. Healthcare providers were also found to strongly influence public attitudes toward vaccination. Overall, improving adult HBV vaccination coverage requires a comprehensive strategy involving health system strengthening, targeted education, and improved access to vaccination services to support global hepatitis B elimination goals.
