Hepatitis A virus capsid protein (HAV) (HAV)

Hepatitis A virus (HAV) is a non-enveloped, positive-sense single-stranded RNA virus belonging to the Picornaviridae family (StatPearls, 2023). The virion consists of a protein capsid composed of structural proteins VP1, VP2, and VP3, which protect the viral genome and facilitate entry into host hepatocytes (UniProt, 2024). These capsid antigens are the primary targets for the host's immune system, specifically for the production of neutralizing antibodies (CDC, 2023). HAV is primarily transmitted via the fecal-oral route and causes acute liver inflammation, often manifesting as jaundice and malaise (NIH, 2023). While there are no specific antiviral drugs for HAV, the capsid antigens are the basis for highly effective inactivated and live-attenuated vaccines, such as Havrix and Vaqta (FDA, 2023). These vaccines stimulate the production of long-lasting antibodies that prevent viral attachment and entry into cells. Passive immunization with human immune globulin also targets these virions to provide post-exposure prophylaxis (WHO, 2022). Understanding the structural integrity of the HAV virion is crucial for both vaccine efficacy and the development of diagnostic serology tests.

Other names

Hepatitis A virus virionHAV surface antigenHepatovirus A capsidVP1 proteinVP2 proteinVP3 proteinVP4 proteinHAV structural proteins

Vaccines containing inactivated or attenuated HAV virions induce the production of neutralizing antibodies that recognize and bind to the viral capsid proteins (VP1, VP2, VP3). This binding prevents the virus from attaching to and entering host hepatocytes, thereby neutralizing the infection. Human immune globulin provides immediate, passive immunity by delivering pre-formed antibodies that target the same capsid antigens.