Researchers from Johns Hopkins recently analyzed several studies of flu vaccination efficacy and concluded that while the vaccines are said to protect 70-90% of the population, in reality, they are only effective in 59%. They analyzed 17 randomized controlled trials and 14 observational studies from 1967-2011. Their conclusions include: efficacy of TIV in only 59% of adults aged 18-65 no such trials for children ages 2-17 or people over 65 fit the criteria for their study; efficacy of LAIV in 83% of children 6months - 7 years and no such trials for ages 8-17; no LAIV studies demonstrated significant protection in healthy adults under 60
One of the researchers argued for reduction of regulatory barriers, stating that,
"'The difference between 69% effectiveness and 90% effectiveness will have a major public health effect in any pandemic that causes serious morbidity or increased mortality.'"
An interesting note is that the researchers only deemed 31 out of 5,707 studies screened as eligible to analyze. They chose to only include studies that used highly specific tests like RT-PCR to confirm the presence of flu and excluded studies on the basis of study design. It is admirable that they had such stringent requirements for their analysis, but that also means they looked at less than 1% of the available studies that have been done in the past 40 years. Are they skewing theirs numbers by being too picky?