Inactivated poliovirus antigen (IPV antigen)

Inactivated poliovirus antigen is the noninfectious form of poliovirus particle used in vaccines for polio prevention. Created by formalin inactivation of whole poliovirus, the antigen retains its structural integrity and key epitopes (D-antigen sites), allowing it to induce protective immune responses without causing disease. The antigen is a complex of four capsid proteins (VP1–VP4), forming an icosahedral particle approximately 30 nm in diameter, with three serotypes corresponding to wild poliovirus strains. The inactivated antigen cannot replicate or cause polio but remains highly immunogenic, making it the cornerstone of the global polio eradication initiative through IPV. This target is not a conventional therapeutic molecular target (such as a receptor or enzyme) but is critical for vaccine-based immunization via humoral immunity. The D-antigen unit serves both as a functional antigenic determinant and a biomarker for monitoring vaccine potency and quality.

Other names

Inactivated polio antigenIPV D-antigenFormalin-inactivated poliovirus antigenD-antigen unit

Induction of host neutralizing antibody response against poliovirus following immunization; Steric blocking of receptor (CD155) binding by vaccine-induced antibodies