CDC: Effectiveness of flu vaccine in seniors only 9%

ATLANTA — This year's triumvirate influenza vaccine was less effective in seniors as compared to the general population, according to the Centers for Disease Control and Prevention's "Morbidity and Mortality Weekly Report" published Friday. Overall effectiveness of the vaccine was 56%, similar to an earlier interim estimate of 62%. 

The adjusted, age-stratified vaccine effectiveness point estimates were 58% for children, 46% for adults younger than 50, 50% for men and women between the ages of 50 years and 64 years and 9% for seniors. 

"These adjusted vaccine effectiveness estimates indicate that vaccination with the 2012–13 influenza season vaccine reduced the risk for outpatient medical visits resulting from influenza by approximately one half to two thirds for most persons, although [effectiveness] was lower and not statistically significant among older adults," the report read. 

For the complete Feb. 22 MMWR issue, click here.