Hepatitis B virus (HBV) is a liver-infecting virus that can cause both acute and chronic hepatitis. While acute infection may resolve spontaneously, chronic HBV infection can persist for years and increase the risk of liver cirrhosis and hepatocellular carcinoma. HBV is transmitted through blood and body fluids, including mother-to-child transmission, sexual contact, unsafe injections, and contaminated sharp instruments.

Because HBV infection is often asymptomatic or presents with non-specific symptoms, laboratory testing is essential for screening, diagnosis, disease monitoring, and assessment of immune status. HBV serological testing detects viral antigens and host antibodies, helping distinguish current infection, past infection, vaccine-induced immunity, and susceptibility.

Current CDC recommendations support one-time HBV screening for all adults using a triple panel consisting of hepatitis B surface antigen (HBsAg), antibody to hepatitis B surface antigen (anti-HBs), and total antibody to hepatitis B core antigen (total anti-HBc). Pregnant women should also be screened for HBsAg during each pregnancy. WHO guidance emphasizes expanded case finding and linkage to care, with quality-assured HBsAg testing as a key approach for HBV diagnosis, using either laboratory-based immunoassays or rapid diagnostic tests depending on the healthcare setting.

Hytest continues to strengthen its infectious disease portfolio with the launch of recombinant HBsAg, Cat. # 8HS15. Building on our experience in HIV, HCV, and existing HBV raw material development, 8HS15 expands our HBV offering and supports our commitment to reliable infectious disease diagnostics and public health.

HBsAg contains a major common antigenic region known as the “a” determinant, located within the major hydrophilic region of the surface protein. This region is shared across major HBV serological subtypes and is the primary target of many anti-HBs antibodies. In addition to the common “a” determinant, HBsAg contains subtype-specific determinants, mainly d/y and w/r, giving rise to classical subtypes such as adw, adr, ayw, and ayr.

Hytest Cat. # 8HS15 is a recombinant HBsAg subtype adw antigen expressed in a mammalian cell line. It is developed for use in anti-HBs immunoassay development, including both sandwich and indirect immunoassay formats.

Clinical Applications of Anti-HBs Detection Include:

• Assessment of immunity to HBV
• Confirmation of vaccine-induced immune response
• Evaluation of recovery after HBV infection
• Support for post-exposure management and vaccination decisions
• Identification of individuals who may remain susceptible to HBV infection

As a recombinant raw material, Cat. # 8HS15 supports a stable antigen supply for assay developers and may help reduce lot-to-lot variation compared with native antigen sources. Furthermore, in an internal sandwich CLIA prototype, Cat. # 8HS15 demonstrated reliable and consistent assay performance, providing quantitative results comparable to those obtained with a commercially available assay (R2 ≥0.95), with high sensitivity and specificity.

HBsAg is a highly conformational antigen, and its antigenic presentation can be influenced by the expression platform through differences in post-translational modifications, folding, particle assembly, scalability, cost, and process complexity.

Cat. # 8HS15 expands Hytest’s recombinant HBsAg portfolio for anti-HBs immunoassay development. Beyond this product, Hytest will continue to develop additional recombinant surface antigens covering different HBsAg subtypes and expression systems. With multiple HBsAg raw material options, Hytest supports assay developers in selecting suitable antigen combinations for different anti-HBs assay designs, helping optimize sensitivity, specificity, correlation, and platform compatibility.

For details, please contact the Hytest Sales team.