Inactivated poliovirus type 2 Sabin (sIPV-2) (sIPV-2)

Inactivated poliovirus type 2 Sabin is a viral antigen derived from the attenuated Sabin strain of poliovirus type 2, which has been chemically inactivated, typically using formaldehyde [1, 2]. It serves as a primary component in Sabin-strain inactivated poliovirus vaccines (sIPV), developed as a safer alternative to conventional IPV (cIPV) which uses virulent wild-type strains [3, 14]. The use of Sabin strains in IPV production significantly reduces the biosafety risk of environmental reintroduction of virulent poliovirus from manufacturing facilities [11, 16]. Biologically, the inactivated virus acts by presenting viral epitopes to the host immune system, primarily inducing the production of circulating neutralizing antibodies (IgG) [10, 18]. These antibodies are highly effective at preventing the virus from reaching the central nervous system, thus protecting the individual against paralytic poliomyelitis [13, 15]. The type 2 component is especially vital in the global polio eradication endgame, as it provides protection against type 2 vaccine-derived polioviruses (VDPV2) following the cessation of trivalent oral polio vaccine (tOPV) use [7, 17]. While sIPV-2 provides robust systemic immunity, it induces limited mucosal immunity in the gut compared to oral vaccines [15, 18]. It is generally administered via intramuscular injection and is associated with a high safety profile, lacking the risk of vaccine-associated paralytic polio [2, 18].

Other names

Sabin-strain inactivated poliovirus type 2Inactivated Sabin poliovirus type 2sIPV type 2Poliovirus type 2 Sabin strain (inactivated)sIPV2

Inactivated poliovirus type 2 Sabin acts as an immunogen that, upon administration, is processed by antigen-presenting cells to stimulate B-cell and T-cell responses. This leads to the production of type-specific serum neutralizing antibodies (primarily IgG) that circulate in the bloodstream. These antibodies neutralize the virus during the viremic phase of infection, preventing its entry into the central nervous system and thereby protecting against paralytic poliomyelitis.