s/o flu vax..science people...efficacy vs. effectiveness

[sbgrace]

Science people...I'm confused about efficacy vs. effectiveness in this flu vaccination study. http://www2.cochrane.org/reviews/en/ab004879.html

 

I went back to look at Cochrane reviews on flu vaxes for kids given the recent post about flu vaccines.

 

First I read this:

From RCTs, live vaccines showed an efficacy of 82% (95% confidence interval (CI) 71% to 89%) and an effectiveness of 33% (95% CI 28% to 38%) in children older than two compared with placebo or no intervention. Inactivated vaccines had a lower efficacy of 59% (95% CI 41% to 71%) than live vaccines but similar effectiveness: 36% (95% CI 24% to 46%).

They mention the flu mist vs. the inactivated. The mist had more efficacy but the same effectiveness in children. So does this mean they are likely equally protected "in real life" from either? That's how I read it.

 

But then their "real language" interpretation says:

 

The review authors found that in children aged from two years, nasal spray vaccines made from weakened influenza viruses were better at preventing illness caused by the influenza virus (82% of illnesses were prevented) than injected vaccines made from the killed virus (59%). Neither type was particularly good at preventing 'flu-like illness' caused by other types of viruses (33% and 36% respectively).

That makes me think I don't have a clue! Should we be getting flu mist then or it doesn't matter?

 

My son's geneticist wants him to do the flu vax this year for the first time because of the H1N1 presently circulating and how it appears to be going this year. He doesn't like live vaxes in his patients with mitochondrial issues but he did have my son do a live vax (MMR) this year because measles is active in our state. He handled it fine. So I believe a live vax (flu mist) wouldn't hurt him if that route is more effective. Is it?

Edited September 20, 2011 by sbgrace