Wednesday, August 31, 2011

Vaccines Get a Thumbs Up: Institute of Medicine Finds Vaccines Generally Safe

Vaccines got the stamp of approval in a new report by the Institute of Medicine. 

I know, not terribly exciting news, but it beats another earthquake or hurricane for those of us on the east coast. 

A panel of experts pulled together by the IOM checked out over 1,000 published research articles and tada! found very little evidence of serious adverse effects.  Their conclusion?  Vaccines are generally very safe.  At least the 8 most common vaccinations in claims reported in the National Vaccine Compensation Injury Program, a national police blotter of sorts for vaccine side effects.

Did I say effects?  Yes, well, you know what the panel (and I) meant - there is no evidence of vaccines causing anything out there.  It's all correlational evidence or in this case, lack of correlational evidence as in not enough convincing evidence, really not enough information to make any conclusion, for the majority of adverse outcomes. 

In fact, most of what the expert panel looked at weren't in fact epidemiological studies but accumulated summaries of case studies that compared to sorting through individual case studies holds some value.  The only large-scale epidemiological research basically focused on the MMR and, you guessed it, autism.   

Not that any of this invalidates the IOM's conclusion.  Under the circumstances they did the best they could. Why are there so few rigorous studies out there? Well the biggies that resolve so much tend towards the pricey and take forever and remember, the really serious adverse reactions rarely occur.  It's hard to investigate very rare events.

Rare events?  Looks like children with compromised immune systems were more likely to experience "side effects" such as brain inflammation, seizures, and anaphylaxsis.  Speaking of high-risk kids, they are one more reason to vaccinate.  They're the ones who really need the herd to be immunized.  I know, if only we knew who they were before we stuck them with needles.

On a side note, the panel didn't look at the risk versus benefits, in fact, didn't so much as glance at the benefits.  They only focused on reports of adverse effects so this report in no way balances risks with benefits. 

If you wanna read more, these media reports didn't do a bad job:
New York Times
Time's Healthland
HuffPo

Anyhow, guess there's one stress to cross of the hypothetical list of parenting perils this fall thanks to the IOM.  Now if I can only convince my daughter she loves the only sneakers left in her size in the tri-state region, I can rest easily until the start of the school year next week. 

2 comments:

scienceofmom said...

I don't know what it will take to put this issue to rest. Like any medicine, vaccines will have side effects on a very small fraction of recipients, and that fact, combined with how being a parent can make a person crazy, will keep people riled about it. I scrolled through some of the comments in the articles you have linked above, and you can see that nobody will trust this report unless they were looking for a reason to relax about vaccines.

Anyway, thanks for your piece on this, and thanks for your blog. I really enjoy your writing.

Polly Palumbo, Ph.D. said...

Howdy SOM! Yes, I know. Those parents already suspicious may focus on the lack of certainty and list of possible reactions.

So glad to "see" another science-minded mom! Love your post on the Freakonomics show. Kept meaning to mention it so happy too see you did!