“Flu season” is winding down and you are happy that you narrowly escaped with your life and health intact. Good thing you had the flu vaccine at your doctor/nurse/pharmacist/HR department/gas station attendent’s wizened advice. Or was it?
It should come as no shock that there is controversy associated with the use of the influenza vaccination. One would think that, after nearly 100 years of use, public health officials should be able to stand high on a pedestal and clearly proclaim that yes, the influenza vaccination protects us. Alas, we’re not even close.
When it comes to the research, there are many ways to look at the data. Truly, few studies come out demonstrating that the flu vaccination clearly protects against hospitilization, influenza and death. Something as simple as the definition of “flu” can affect outcomes. The is laboratory confirmed influenza viral infection and then there is “influenza-like illness,” which does not require confirmation and assumes that certain symptoms at a certain time of year are from the flu.
Several recent studies include:
- Flu vaccination effectiveness in children
- Flu vaccination effectiveness in the elderly
- My personal favorite – the Cochrane Collaboration review that pretty much sums it all up
This particular study looked at the data in a different way in an attempt to negate the effect of bias by using instrumental variable methods. Researchers looked at a rather massive amount of data (almost 13 million person influenza seasons) and concluded that, when this method was used, effectiveness of the flu vaccination at preventing death during the flu season at 6% (down from 33% without this method). Pretty dismal.
What becomes even more interesting is when researchers looked at what happened after the flu season was over. Without this method, the vaccination lowered the risk of death by 15%. However, when the data was looked at using the instrumental variable method, the risk of death actually went UP 13%.
So, while you may have a lower risk of dying during the flu season, any benefit gained may be overridden by a much greater risk of death after flu season.
Things that make you go “Hmmm….”