Hepatitis A Virus capsid protein (HAV capsid) (HAV capsid)

The Hepatitis A Virus (HAV) capsid is the proteinaceous shell of the virus, primarily composed of the structural proteins VP1, VP2, and VP3 (UniProt: P03300). This capsid contains a critical receptor-recognition site that facilitates viral entry by binding to the host cell receptor, Hepatitis A Virus Cellular Receptor 1 (HAVCR1), also known as TIM-1 (Wang et al., Science, 2015). Vaccine-induced antibodies, such as those elicited by inactivated HAV vaccines like Havrix and Vaqta, target a highly conserved neutralizing epitope on the capsid surface that overlaps with this receptor-binding site (Cao et al., Nature Microbiology, 2019). By binding to this site, antibodies sterically hinder the virus's ability to attach to host cells, effectively neutralizing the infection (WHO, 2022). The stability and conservation of this site explain the long-term efficacy of HAV vaccines across different viral genotypes (CDC, 2020).

Other names

HAV receptor-recognition siteHAV neutralizing epitopeHAV VP1-VP2-VP3 complexHepatitis A virus polyprotein

Neutralizing antibodies bind to the capsid surface, sterically hindering the interaction between the viral receptor-recognition site and the host cell receptor (HAVCR1/TIM-1), thereby preventing viral entry (Wang et al., Science, 2015; Cao et al., Nature Microbiology, 2019).