Why are older adults and individuals with underlying chronic diseases in Germany not vaccinated against flu? A population-based study.

Background Older adults and individuals with underlying chronic diseases are at increased risk of developing influenza-related complications and are target groups for seasonal influenza vaccination in many countries. In Germany, an annual national information campaign is conducted to increase influenza vaccination uptake in the target groups. However, data are lacking on knowledge and attitudes toward influenza vaccination among older adults and those with chronic diseases. The present study aimed to (i) estimate influenza vaccination uptake for the 2012/13 and 2013/14 seasons, (ii) assess knowledge and attitudes about influenza vaccination, and (iii) identify factors associated with vaccination uptake in two risk groups.