Fractional-dose IPV in Polio Eradication.

The development of fractional-dose inactivated poliovirus vaccine (fIPV) has been crucial to the global polio eradication initiative (GPEI) in the past decade, providing a dose-stretching and affordable option to enable global inactivated poliovirus vaccine (IPV) introduction. In April, 2016, the type 2 component of oral poliovirus vaccine (OPV) was withdrawn from routine immunisation because of the risk of vaccine-derived poliovirus and vaccine-associated paralytic poliomyelitis, and the trivalent OPV was replaced with a bivalent form.