January 8, 2015Why did my flu vaccination fail?
Getting the flu vaccine is akin to making a safe gambling bet. Of course you would double down with a pair of face cards showing when the dealer has a 6. As with other non-tangible bets (insurance & entertainment), we have some ingrained sense of the risk/reward equation.But you don’t always win.
As for me, I did not plan on spending my last 6 days of Christmas break lying in bed fighting chills, muscle aches, fever, hellacious cough, sneezing and wheezing – desperately waiting to feel better. And yes, I received the influenza virus vaccine.
So how effective has the seasonal flu vaccine been in recent years?
Historically, the CDC has stated that the influenza vaccine is ~60-80% effective against the prevailing strains. With the current batch listing at ~42% match, we are not doing so well (literally). Dr. Alan Fauci, Director of the Institute of Infectious Diseases has recently indicated it as only about 33% effective
In the 2009-10 “Flu Pandemic” (the first in 40 years), the prevailing strain was so mismatched that seasonal vaccine effectiveness could not be performed! In that year, there was a SUPPLEMENTAL (H1N1) vaccine and it was about 62% effective.
What would an appropriate flu vaccine efficacy threshold be? ACIP Guidelines have used the 60-80% effectiveness numbers – and indeed from 1987 – 2006, there were only three years with poor efficacy
How will the 2014-15 flu vaccine net out? In many CDC Sentinel Surveillance sites, it appears we have already peaked, the results are ugly. Not only was the vaccine a poor match, but the prevailing strain (H3N2) was of the severe variety. The bad news was that it was a failure, and the prevailing strain did not fully appear until the vaccine was in development. The good news is that the “below par” efficacies of the last 4 years’ vaccines will likely force the WHO and CDC to change their forecasting methods.
Gambling with mismatched flu vaccines using outdated technology is worrisome. Dr. Michael Osterholm, Director of the University of Minnesota center for Infectious Disease Research and Policy, has raised the issues of using archaic science
We need to get flu vaccine efficacy back above 60%.