Maybe not to the Somali refugee toddler himself, who bellows as a needle stings one chubby thigh at Dadaab Refugee Camp in Kenya. But the prick of that needle means we are one crucial step closer to protecting children all over the world against the paralyzing effects of polio. Rarely has the sting of a needle been so welcome.

On 28 February, UNICEF concluded a landmark tender process to make inactivated polio vaccine (IPV) affordable and accessible to 73 countries eligible for support from the GAVI Alliance (Global Alliance for Vaccines and Immunization). As the last few polio-endemic countries continue to eradicate polio, IPV is being supplied to a growing number of countries. IPV is injected (as opposed to oral polio vaccine, or OPV, which is provided orally), and it eliminates the miniscule risk of vaccine-derived poliovirus. As such, introducing IPV is an essential element of the Polio Endgame Plan, which requires the eventual phased removal of all OPVs to secure a lasting polio-free world,

IPV will now be available to 73 GAVI-supported countries for as little as €0.75 per dose (about $1 per dose at current exchange rates). To help support middle-income countries in making the shift to IPV as well, 10-dose vials will be available through UNICEF, beginning in July 2014, at a price of €1.49-2.40 (about $2-3.28). In total, more than 120 countries are currently using OPV alone.

In this video, Somali refugee children at Kenya’s Dadaab Refugee camp were vaccinated with both IPV and OPV for the first time ever, as were children in surrounding host communities. In the vaccination round depicted here, which was held in December, 2013, a total of 120,000 children under the age of five were given IPV and 530,000 received OPV.

Children like the Somali toddler, shown in the video, may be too small themselves to understand the benefits. But the sting of that needle, multiplied by children all over the world, signifies a giant leap toward ridding the world of polio for good.