Sharyl Attkisson, in a 2006 CBS News report on Flu Shots

Sharyl Attkisson, in a 2006 CBS News report: "Over 20 years, the percentage of seniors getting flu shots increased sharply from 15% to 65%."

"Flu deaths among the elderly should have taken a dramatic dip... Instead, [they] continue to climb."

If flu shots are effective, how could that possibly be the case?