Poliovirus type 1 (Sabin strain) capsid protein (PV1 (Sabin) capsid)

The Sabin poliovirus type 1 capsid antigens are the structural proteins (VP1, VP2, VP3, and VP4) that form the icosahedral shell of the attenuated Type 1 poliovirus strain used in the Oral Poliovirus Vaccine (OPV) (PubMed, PMID: 16894057). These proteins are responsible for protecting the viral RNA genome and facilitating the attachment of the virus to the host cell receptor, CD155, which is the first step in the viral life cycle (UniProt, P03300). In the context of immunization, these capsid antigens act as the primary targets for the host's immune response, specifically inducing the production of neutralizing antibodies that prevent subsequent infection by wild-type polioviruses (StatPearls, NBK554540). While these antigens are essential for the efficacy of the Sabin vaccine, the strain's genetic instability can lead to mutations that restore neurovirulence, resulting in vaccine-associated paralytic poliomyelitis (VAPP) or circulating vaccine-derived polioviruses (cVDPV) (WHO, 2023). Consequently, these antigens are also the focus of research into more stable, next-generation vaccines, such as the novel oral poliovirus vaccine type 2 (nOPV2) and similar candidates for type 1 (Nature, 2020).

Other names

Sabin 1 capsidPoliovirus type 1 structural proteinsVP1-VP4 proteins of Sabin 1Live attenuated poliovirus type 1 antigenPoliovirus type 1 (Sabin) polyprotein

Vaccines containing these antigens induce the production of neutralizing antibodies that bind to the viral capsid, preventing the virus from attaching to the host cell receptor (CD155) and entering the cell; antiviral agents like V-073 bind to the capsid to prevent viral uncoating or assembly.