Flu causes close to 1/2 of lost workdays and low productivity in adults 50-64 during flu season
During influenza season, influenza-like-illness is responsible for 45% of workdays lost and for 49% of low productivity days among working adults aged 50–64 years.
Nichol, Kristin L., Sarah J. D'Heilly, Michael E. Greenberg, and Edward Ehlinger. Burden of Influenza-like Illness and Effectiveness of Influenza Vaccination Among Working Adults Aged 50-64 Years. Clin Infect Dis. 2009; 48(3): 292-8. http://cid.oxfordjournals.org/content/48/3/292.long