You have 100 doses of a vaccine against a deadly strain of influenza that is sweeping the country, with no prospect of obtaining more. Standing in...

You have 100 doses of a vaccine against a deadly strain of influenza that is sweeping the country, with no prospect of obtaining more. Standing in line are 100 school children and 100 elderly people. The elderly are more likely to die if they catch the flu than the school children are. But the elderly have fewer years left to live as compared to the school children, who have their whole lives ahead of them. 

Which group do you vaccinate? 

Describe each step in your decision-making process.