Without proper refrigeration at remote clinics, getting vaccines to children takes meticulous planning and dedication. Every Tuesday morning, Mustapha Shuaibu arrives at his clinic with a small light blue cooler of vaccines, ready to immunize the babies strapped to the backs of their mothers, who will soon be lining up outside.

In February, New Incentives received exciting news: GiveWell recommended a grant of up to $4.8 million to provide oral rehydration solution for babies enrolled in their program in Nigeria. This grant will enable caregivers to treat childhood diarrhea, a leading cause of death in children under five. As they embark on this critical work, they're sharing some of the lessons they've learned and the refinements they're making to their approach.