Hepatitis E virus is (HEV) an important cause of severe acute hepatitis in human.It is a non-enveloped single-strand RNA virus.Cryo-EM of virus-like particle showed the virus capsid is made up of subunits (capsomeres) consisting of homodimers of the structural protein encoded by ORF2.Our previous studies showed that the minimum dimeric domain of HEV capsid protein is located on ORF2 aa 459-602 and contains the neutralizing sites of the HEV.At least two HEV neutralizing sites were defined by monoclonal antibody 8C11 and 8H3, and 8C11 was found to strongly block HEV from both the binding and infection to host cells and to be regarded as recognizing a putative receptor-binding site.Recently, the recombinant capsid protein E2s (aa 459-602) has been crystallized and resolved as X-ray structure in 2.2 (A) resolution.