Influenza Vaccination Campaigns: Is an Ounce of Prevention Worth a Pound of Cure?

This paper estimates the overall impact and externality effects of an influenza vaccination program expanding coverage outside the typical target group. Using a triple-difference design, which exploits the introduction of a broad based vaccination program in Ontario and the quality of the vaccine from year to year, I link higher vaccination to health improvements. Results indicate coverage expansion leads to large excess gains for program-regions; benefits exhibit decreasing returns corresponding to a standard model of disease dynamics; and substantial external benefits accrue to older adults.