Over the past 15 years, Tanzania has made a concerted effort to immunize its children -- and has achieved a remarkable vaccination rate of almost 90 per cent. That's not good enough for the government and health organizations, though. They want to get as close to 100 per cent as possible. But figuring out which children have been missed is a huge challenge in a country where many families still live nomadic lives in remote areas. Enter Seattle health organization PATH and Canada's own Mohawk College, in Hamilton, Ont. They're helping out, not with more vaccines or nurses, but a database.