Monday, December 03, 2012

NIVW 2012



Credit CDC


# 6759


Regular readers of this blog know by now that I get the flu vaccine every year, and that I encourage others to do the same. Not because the vaccine is perfect (it isn’t), but because it is the best preventive measure we have available to us at this time.


This week (Dec 2-8)  is National Influenza Vaccination Week (NIVW), the CDC’s annual attempt to reach flu vaccine holdouts before the heart of the flu season arrives.


So this week, you’ll be hearing a lot about the flu vaccine on the news and online.


The theme this year is It’s Not Too Late To Vaccinate.


The CDC will hold a Twitter chat on Wednesday, December 5th, from 1-2pm EST hosted by Dr. Mike Jung. You can participate or follow the conversation via the twitter hash tags @CDCFlu and #NIVW2012.


And you’ll find videos and promotional materials on the National Influenza Vaccination Week website, including:



I’d be remiss if I didn’t point out that In this year’s NIWV talking points, noticeably absent are any estimates of vaccine effectiveness.


Flu campaigns in the past have touted that for healthy adults under the age of 65, in years when the vaccine is a good match to circulating strains, effectiveness ranges from 70%-90%. This year, that message is replaced with a more generic:

The flu vaccine is the best way modern medicine currently has to protect against this potentially serious disease.

a.  While how well flu vaccines work can vary, the findings of many studies from multiple countries across age groups support the benefits of vaccination, especially during years when the vaccine is well-matched to circulating viruses.

The reason for this change is that studies in recent years have shown the effectiveness of the flu vaccine to vary considerably from year-to-year, and among different age cohorts.


A little over a year ago, CIDRAP’s  Comprehensive Flu Vaccine Effectiveness Meta-Analysis) found the trivalent inactivated vaccine (TIV) had a combined efficacy of 59% among healthy adults (aged 18–65 years).


Among children aged 2-7, the LAIV proved more protective, showing efficacy in 9 out of 12 flu seasons (75%) with a pooled efficacy of 83%.


Not awful, but not terrific either. This is a problem we’ve covered many times before, including:


CID Study: Effectiveness Of 2010-11 Flu Vaccine

Study: Flu Vaccines And The Elderly

Flu Shots For The Elderly May Have Limited Benefits



All of which makes issuing blanket statements about the vaccine’s effectiveness problematic. While I might prefer the CDC could find a way to be more precise, I have to admit are simply too many caveats and exceptions to fit into an easily deliverable press meme.


Despite their limitations, flu shots have an excellent safety profile (see Harvard Study Reaffirms Safety Of Flu Vaccine), and remain one of the most important steps we can take to avoid catching influenza each year.


Of course, flu shot or not, practicing good flu hygiene is important, too.  Washing your hands frequently, covering coughs & sneezes, and staying home when sick.


Flu shots are like seat belts in your automobile. They may not guarantee you’ll walk away from a collision unscathed, but they certainly improve your chances.  


Which is why I buckle up every time I get into a car, and why I get the flu shot every year. Not because I’m 100% certain of a good outcome, but because sometimes you’ve just got to play the odds.

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