The Global Polio Eradication Initiative has done well to introduce 3 doses of the Inactivated Poliovirus Vaccine in Afghanistan

Smallpox eradication illustrated the critical importance of high vaccine efficacy (VE) of the smallpox vaccine in rich and poor countries. Polio eradication was made possible with the inactivated poliovirus vaccine (IPV), as it also exhibits high VE in rich and poor countries. Oral polio vaccine (OPV), with very low VE in tropical low/middle income countries (LMICs), was an inferior tool. Nevertheless, the global polio eradication initiative (GPEI) used trivalent OPV (tOPV) exclusively in LMICs from 1988, when the World Health Organisation (WHO) resolved to eradicate polio by 2000. The VE of tOPV was highest against type 2 and lowest against type 1 polio. Unsurprisingly, wild poliovirus (WPV) type 2 polio was eradicated in 11 years (1999) and type 3 polio in 24 years (2012). To date, type 1 remains endemic in Afghanistan and Pakistan, despite many dozens of supplementary immunisation campaigns. In 2025, GPEI and the Government of Afghanistan introduced fractional doses of IPV in each of three campaign rounds in one large region, using needle-free intradermal inoculation devices. This was reportedly well-received by health staff and the community. The realisation that IPV is the right tool opens the door to move rapidly towards elimination of wild type 1 polio in Afghanistan and Pakistan, as well as for stopping use of OPV and its attenuated version of novel OPV, both of which evolve into circulating vaccine-derived poliovirus (VDPV) that causes polio outbreaks. However, the needle-free intradermal device is expensive and not required for subcutaneous and intramuscular inoculations with other vaccines, making this tactic not scalable in all of Afghanistan or replicable in Pakistan. Currently polio is caused by WPV, VDPV and OPV directly as vaccine-associated paralytic polio. We recommend routine use of three full doses of IPV given as a combination product with the currently used pentavalent vaccine, i.e., hexavalent vaccine to avoid giving extra injections, so that GPEI can use it to stop all polio in all LMICs.