Estimates of influenza vaccination target population sizes in Spain for the 2006-2007 season

We thus conclude that approximately 18 million persons, 41% of the Spanish population, should receive influenza vaccination in the 2006-2007 season under present Spanish guidelines. With the estimated number of doses to be distributed during this season (10 million), compliance with current recommendations would amount to only 56% at best. Extending universal vaccination to the 50-64 age group should be considered as an option for improving influenza vaccination coverage, particularly among high-risk patients, because a greater proportion of persons would receive the recommended dose by becoming eligible for the more effective age-based strategies.