People in the Keny cattle camp in the county of Rumbek walk towards a team of vaccinators who have just arrived. They are part of National Immunization Days (NIDs) in early 2001 that are being carried out at the same time as campaigns in nearby countries.

Health workers fill plastic containers with water that will then be frozen so that vaccine can be safely stored in cold-storage boxes for transport. Mass immunization campaigns in southern Sudan begin just beyond the Kenyan border in Lokichoggio, the supply and logistics nerve centre of the Sudan relief operation. These cold-storage boxes help keep polio vaccine frozen for at least seven days.

A UN flight carrying oral polio vaccine arrives in the town of Rumbek. From here it will be delivered to various centres for pick-up by immunization teams. At each stage, the vaccine is transferred to smaller containers, part of the relay storage system called the 'cold chain'.

A baby is immunized in the village of Wumpul in Rumbek county.

A girl suffers from an eye infection in Rumbek county. The polio eradication effort has been a springboard for promoting other health interventions. Since 1999, campaigns against polio have also distributed vitamin A which helps strengthen immunity to all diseases. This distribution is credited with saving the lives of up to one million children.