A Drunken Madman

They're not as smart as they'd like you to think, these antivaxers.

The latest salvo in Meryl Dorey's Twitter War against vaccination:

Polio surge in Nigeria after vaccine virus mutates - Yahoo! News: Polio surge in Nigeria after vaccine virus mut.. http://bit.ly/DhFf0

Whoah, scary headline. And it's true. A poorly-implemented polio vaccination program in Nigeria does appear to have caused the emergence of some new genetic variants of Polio. This is scary. Surely this means that all vaccinations are suspect now?

Well, no.

You see, Nigeria still uses an old, outdated, live polio vaccine because, basically, it's cheap. Cheap as chips. Trouble is, there are... problems with it.

Turns out that the weakened polio particles get passed through immunized kids, they can find their way into the local water supply, the usual way. Other kids will then pick up those self-same weakened particles and, usually, gain a small level of immunisation.

Here's a very interesting sentence from later in the article though:

But in rare instances, as the virus passes through unimmunized children, it can mutate into a strain dangerous enough to ignite new outbreaks, particularly if immunization rates in the rest of the population are low.

[emphasis mine]

This is a problem inherent in the live vaccine approach to polio in a country with poor sanitation. The germs just keep on coming back, and when they keep coming back they have time to survive and multiply. And when organisms survive and multiply, they evolve. And when unimmunised children come into contact with the newer, tougher germs, well, it's polio time!

Immunologists know this, and that's why here in the rich-ass west, we generally use a safer, inactivated polio vaccine - and when we do use the live vaccine, we have the sanitation infrastructure to ensure it doesn't turn zombie and come back. Problem is, Nigeria can't afford the inactive version. They're using the old, outdated, known-to-be-problematic vaccine. And whaddaya know, they haven't got the plumbing fixed either. There's not a bidet in sight!

So first of all, old technology. But that's not the only item that undermines Meryl's argument. You see, there's a thing called Herd Immunity. AVN supporters are very fond of claiming that Herd Immunity is bunk, and that it's OK for them to leave their kids unimmunised while the "sheeple" can just carry on lining up for jabs, and there'll be no problem.

BULLSHIT

The actual cause, if you read the article, aside from cheap vaccine and poor sanitation, is incomplete vaccination - exactly what Meryl and her followers seem to want to happen here.

Another quote from Meryl's linked article:

Until a better vaccine is ready, WHO and U.S. CDC officials say the oral vaccine is the best available tool to eradicate polio and that when inoculation rates are nearly 100 percent it works fine.

"Nigeria is almost a case study in what happens when you don't follow the recommendations," Kew said.

So, basically, this entire event can be attributed not to vaccines, but to a combination of:

• Incomplete vaccination
• Poor Sanitation
• National scale poverty
• Poor implementation

So Meryl has footbulleted again, though if you're an indoctrinated antivaxer, you'll probably miss it as you skimmed the article, as I suspect Meryl did.

I'll close out with this point: The WHO, in conjunction with local and national public health authorities, is on a worldwide mission to eradicate polio entirely. Sadly, this goal is being stymied by lacking political will, by paranoia about vaccines and by poor implementation of programmes in the developing world. Meryl is not helping.

As ever, the twitter backlash against the Australian Vaccination Network continues. One particular item has grabbed my attention. @nocompulsoryvac, a twitter account run by Meryl Dorey on behalf of the AVN, tweeted this little gem today, on a claimed 155% risk increase for Autism.

Well, this piqued my interest. That's a fairly spectacular figure, representing a significant 2.5x increase in risk. Wow. And it's quite a specific number too. Must be conducted in quite a rigorous manner, eh?

Well, no. Not really.

You see, even though Meryl left that little gem unattributed*, I decided I was going to hunt down this data point and see if it was really all it was cracked up to be.

So off I went to my favourite search engine, and typed in "155% autism risk vaccine". And what do you know? I found the "study", first result out of the gate.

It turns out that the rigorous, statistically controlled, epidemiological study in question was... a phone survey. By a marketing company. Funded, to the tune of US$200,000 by... Generation Rescue, a partisan antivax organisation founded by a ditzy celebrity and dedicated to proving the MMR/Autism link by any means possible.

Oh I'm sorry, did I say all that? I meant concerned parents' group honestly investigating the MMR/Autism link.

DING-A-LING-A-FUCKING-LING

So aside from the immediate issue with how a poorly designed phone survey somehow gets conflated with real medical research, there are other issues. It seems there was no medical follow-up to confirm diagnoses, no control for known risk factors such as past familial neurological trouble, no reporting on exactly what the poll questions were, and finally no review of the data by any other group - all of which raise serious flags about the reliability of said "study"

But do you know what the best part was?

No, really? Do you want to know?

Well, it seems Meryl can't even report her own partisan studies correctly. The actual results are summarised in the article thusly:

-- Among more than 9,000 boys age 4-17, vaccinated boys were 2.5 times (155 percent) more likely to have neurological disorders, 224 percent more likely to have attention deficit hyperactivity disorder, and 61 percent more likely to have autism.

-- For older vaccinated boys in the 11-17 age bracket, the results were even more pronounced. Vaccinated boys were 158 percent more likely to have a neurological disorder, 317 percent more likely to have ADHD, and 112 percent more likely to have autism.

I've highlighted where Meryl fucked up, not because I think that you, dear reader, are a bit thick, because you're not. You're smart and good looking, and probably get far more casual sex than the average person. I highlighted in in case Meryl comes by, because, you see, she needs help. Meryl's target figure (autism) was 61%. 155% referred to all 'neurological disorders', including the rather fluffily defined ADHD.

Now, it's been a while since I did Statistics 101, but the numbers also seem a little skewed, and oddly reported. The two age groups quoted, for example, are actually just one group, with a subset pulled out to highlight the intended result. What we have is 4-17, and the subset 11-17. What are the numbers for the 4-11 group? We're not told, but we can extrapolate, and someone clever with Maths could probably tease out the numbers. Yes, folks, the 4-11 numbers WOULD be lower, significantly lower, than either of the two groups we quoted. There's no way around that. If your overall sample set has a 61% rate, but one half has a 112% rate, what does the unreported group have? That's right, an even lower rate**. So MMR (and other vaccines) are administered around school starting age, and then very little happens until the age of 11. That's stretching post-hoc ergo propter hoc a bit far, even for Meryl.

Secondly, what we're quoting here is a percentage increase in a rate that itself is not reported. Dr Ben Goldacre devotes an antire chapter of "Bad Science" to "Bad Stats", and this is precisely where he starts out. The number best suited to this kind of reporting is the 'Natural Frequency', that is a number such as "1 in 5000 people". However it's far more sensational, if your study gives you small results, to report the 'relative risk increase'. Let's just break this into another paragraph to make this a little easier, and just make up a hypothetical study of 10,000 subjects

• Background rate of event: 1/10,000, or 100 per million
• Reported rate for study: 3/10,000, or 300 per million
• Relative Risk Increase: 300%

Fuck! 300%! Call the cops! Call the fucking coastguard! Do something! That's a 300% fucking increase!!! Aaaaaaagh!

No, wait. That's an increase of only two reported cases per 10,000 results. We just managed to find two more people than we expected by chance. Out of 10,000 people. That's almost certain to happen if you run more than one study.

This is entirely statistically insignificant. But it's a 300% increase. That's even more then Generation Rescue found in their study. Holy crap, I'm onto something!

Not only that, given that the incredible publicity being generated around the purported vaccine/autism link, I would positively expect misreported results in this kind of survey. A kid that misbehaves a little, in the mind of a mother exposed to too much Jenny on Oprah, is suddenly an ADHD case. A socially awkward kid is suddenly autistic. You can see where I'm going here.

In fact, given the methodology and the background surrounding this specific manufactured 'controversy', I'm really, really surprised the numbers weren't even more skewed.

So, in summary, Meryl is lying again. SURPRISE!

* If there's one thing antivaxers are good at, it's making assertions without attribution. For a period on the AVN's FaceBook page, I made it my business to correctly attribute quotes lifted wholesale by AVN supporters.
** Math geeks, I'm not sure I got the calculations correct, but is it possible there would be a negative result in the lower group?