Thursday, October 28, 2010

Vaccines and autism

Recently, there have been various vaccines that have been “linked” (using the most loose meaning of the word) to autism. One is the MMR vaccine, and another is basically any vaccine that includes thiomersal(with special attention given to influenza vaccines). There has been great public outcry and uproar about these vaccines, with various pundits and spokespeople and “celebrity personalities” making all manner of claims about them. As a result, many people have been frightened away from vaccines. Just how justified are these fears, though?

First, we need to know what these vaccines are. The MMR (mumps, measles, and rubella) vaccine is actually three vaccines in one. It consists of viruses from each of those three diseases. That might sound like a rather odd way to keep people from being infected with measles and mumps viruses, but it works by infecting people with very mild versions of the viruses. The mumps and measles viruses, for example, are grown for the laboratory in chicken eggs. This means that the type of viruses are well-suited for living in chickens. People, however, are not poultry. When a virus that is optimised for living in a chicken is injected into a human, it is not a happy virus. It does not do well.

The viruses are kept in solutions solutions containing any of the following: table salt, vitamins, amino acids, beef serum, table sugar, phosphate, gelatin, sorbitol, and a human blood protein that is grown in yeast cells (they make it in yeast cells rather than get it directly from actual human blood because it is easier, safer, and it doesn't use up blood supplies that are otherwise needed for transfusions; it is identical to what is in the human body, though). Neomycin is also added to keep bacteria from growing. Nothing too exotic, really, although obviously there is the risk of some people having an allergic reaction to traces of egg or gelatin or neomycin or whatnot. Autism is not an allergy, however, and anybody administering the vaccination is supposed to be aware of the possible allergic reactions and to be sure that nobody who will drop dead from exposure to, say, gelatin gets the shot. No preservative is used in the vaccine, because preservatives could kill the weak viruses and make the vaccine ineffective. Instead, the vaccine is freeze-dried for storage and shipment, and then reconstituted shortly before being used. Since viruses are basically just genetic code in an armoured shell, freeze-drying them does no damage to them at all.

Typically, the vaccine is given at a very early age, and then a second dose is given several years later. The second dose is not a booster shot, and most children could actually get by without it. The problem is that in a small number of cases the first shot doesn't “take”, and a second shot is needed to effectively vaccinate those kids. It is considered safest to go ahead and give all kids the second shot even though the first one probably already worked, because people figure it is better to be certain than to risk even a small chance of a kid being susceptible to the diseases.

There is no real reason why all three disease vaccines have to be given in one shot. It is mainly a case of there being no real reason not to do so, and so pediatricians decided that it would be best to only traumatise kids with having to get one shot rather than three separate ones.

The three individual parts of the vaccine were all developed way back in the 1960's, and in 1971it became standard to use the combination of the three. So the vaccines have been used for about 45 years or so, and the combination for 39 years. It has been around for a fair bit of time. Millions of people heading into middle age have had the vaccine.

Why, then, was there suddenly a big panic in the late 1990's about it?

The answer is that there was a doctor in England, by the name of Andrew Wakefield. He published an article (another source has it displayed in full without need to sign up here) in the medical journal The Lancet concerning autism and the MMR vaccine. Since then, there has already been a ton of information published revealing subsequent follow-ups to that article, the discovery that Wakefield was basically paid by a law firm to discredit the vaccine, the complete failure of all similar tests since then to come up with the same results, and so on. It is pretty much taken for granted now that the article and Wakefield's later claims are at best dishonest and at worst totally false. Since this has already been so thoroughly covered elsewhere, I'll not get into details of it.

Because none of it really matters. Even if Wakefield was a certifiable saint, and his paper had instead been the epitome of scientific rigour and integrity, it wouldn't matter.

Wakefield has in the last twelve years gone around loudly protesting about the MMR vaccine and scaring countless people away from vaccinating their children due to fears of autism. . .yet his paper never actually linked the vaccine to autism. It found no connection between the two things. None. Even after having quite probably secretly “adjusted” his data in the report, he was unable to show any indications that the MMR vaccine can cause autism. Behind all of the fuss and trouble and illness and death that he has caused, his basic claim is not that the vaccine was found to cause autism. It's not even that the study suggests that the vaccine causes autism. It was that his test didn't show that the vaccine didn't cause autism. Everything he's said and written is based on his vague suggestion that perhaps maybe the vaccine might in some mysterious way, that he saw no indication of but that he attributes to mixing the three viruses, cause autism.

This paper of Wakefield's is the basis of pretty much all the hysteria about this one vaccine. And it never actually concluded anything against the vaccine.

No study has ever found a link between the MMR vaccine and autism. Not Wakefield's (even when he seems to have intentionally stacked the deck to try to do so), nor any of the many subsequent ones. In fact, whenever anything definite is able to be concluded, it is that rates of autism have nothing to do with vaccination at all. Take this study from Japan, for example. The country stopped giving the mixed vaccine and started giving them as individual shots in 1993, years before Wakefield's paper. According to Wakefield, it is the combination of all those vaccines mixed together that is causing autism rates to climb. According to Wakefield's claims, the reported autism rates should drop if the vaccines are given individually rather than as a mixture.

Guess what the reported autism rates did when Japan stopped giving the mixed vaccine? They did exactly the same thing as the autism rates did in countries that still used the mixed vaccine. They kept climbing.

Wakefield's paper didn't find any evidence that the vaccines have no influence on autism rates. Other papers did find that evidence. That's about as conclusive as things get.

The mass hysteria about MMR vaccines is based on a flawed study that didn't report what people think it did and that has since been outdated.

And yet Wakefield still goes to rallies and sells his books trying to scare people away from the vaccine, and thanks to his influence the rates of measles, mumps, and rubella (rates that have been conclusively linked to the vaccine: the vaccine pretty much eliminates those rates) have skyrocketed. Thousands of kids have been hospitalised. Many have been permanently affected, such as by brain damage. And a few have died.

Yes, there are some risks to the MMR vaccine. These risks are the same whether you get the vaccines all as one or separately, though, and the risks are known to the people producing, distributing, and administering the vaccinations. They're also known to any parent who takes the time to read the warnings that the vaccines come with.

The risks, however, are far less than the risks of leaving a kid unvaccinated. Even if everybody else in a country has been vaccinated and the disease has been eliminated from that country, you're not safe. There have been many flare-ups of measles in the US, for example. . .most of which involved people bringing the disease from overseas. People who were never vaccinated keep getting the diseases, even in the relative safety of the US. And these diseases are far from harmless. The risks from the vaccine are very unlikely, and pale in comparison to the risks that come with measles.

There has been nothing to connect MMR vaccines to autism, and plenty that suggests no connection. There has been an overwhelming amount of evidence showing that MMR vaccines save the lives of countless people.

The whole scare is based on nothing.

What about the big thiomersal (aka thimerosal) scare, then? Thiomersal is basically mercury, which everybody knows is bad for you, right? So surely the worries about thiomersal in vaccines are warranted, right?

Well, first of all, thiomersal isn't mercury. It contains mercury, but it isn't just mercury.

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Thiomersal is nine parts carbon, nine parts hydrogen, one part sodium, two parts oxygen, one part sulphur, and one part mercury. That's one atom out of twenty-three. Just because a molecule has an atom in it that is dangerous, that doesn't mean that the molecule as a whole is going to be dangerous in the same way. The qualities of each individual atom do not always show up in the combined molecule. For a good example, consider sodium chloride. In other words, table salt. Pure sodium explodes violently in the presence of any moisture. And yet countless chefs throughout history have safely thrown large quantities of sodium chloride into pots of water with no drastic consequences (unless you count high blood pressure). So just because thiomersal has mercury in it, that doesn't mean that thiomersal acts like mercury.

As it happens, thiomersal is dangerous. In fact, it wouldn't be much use if it wasn't. But what matters is just how it is dangerous. There has been no sign that thiomersal causes the same health problems that you find in mercury poisoning. It is indeed a poison, which is why it has been used in vaccines; it helps keep anything unwanted from growing in the mixture. Again, though, just because something is a poison doesn't mean it is going to be dangerous. Again, we can consider table salt. Even though table salt doesn't explode when it gets wet, it still can cause bad things to happen to you. Salt can cause your blood pressure to do horrible things, can kill cells, can dehydrate you, and all sorts of other not fun things.

At the same time, though, salt is an essential for life. You couldn't live without salt.

The key is not just the substance itself, but the amount of the substance. A little bit of salt is good for you. Too much salt is bad for you. For countless other chemicals, it is a similar story: in small amounts, it is either beneficial or does nothing to you. In high doses, it can kill you. Pretty much every vegetable we eat, for example, is full of all sorts of horrible ghastly toxins. Yet it isn't often that somebody falls over dead from eating a slightly undercooked potato. That's because the toxins are in such small quantities, and people are such big critters, that there's not enough of the toxin to do anything to our bodies.

This property extends to all chemicals or substances, really. There's a certain amount that is harmless, and then there's a certain point beyond which it gets dangerous.

Thiomersal is dangerous. If you work in a factory where it is made and you spill a vat of it, you can get sick or die from the fumes or from getting it all over you. But the amount that is found in a vaccine is tiny. It is enough to kill tiny things, such as fungi and bacteria. It is not enough to do anything to a human. So you're not going to fall over dead from sniffing thiomersal-containing vaccines or from spilling them on you (unless the vaccines contain some other horrible stuff along with the thiomersal, though I have yet to hear of any vaccines made with curare or puffer-fish venom).

So thiomersal isn't a problem, any more than is the tiniest scattering of uranium atoms that are, without question, all over you right now. However, there is an added complication. Thiomersal doesn't remain thiomersal. When it is injected into the body, it is thiomersal. But the body takes the stuff and breaks it up and mixes it around and changes it. The molecule gets torn apart. It gets made into smaller molecules. And one of those molecules is a thing called ethyl-mercury.

Now we have something that is actually called mercury, even by scientists and medical people. And we've all heard countless times about how even tiny traces of mercury in seafood can be bad for us, about how it can gradually build up in our bodies, and so on. So now we should be worried, right?

Well, not yet. Mercury, you see, tends to not sit around as pure mercury in nature. Mercury atoms don't really like each other, and prefer to find other different atoms to be friends with. Mercury atoms tend to form into molecules with other non-mercury atoms. Carbon and hydrogen are big favourites. The two big important such molecules are ethyl-mercury and methyl-mercury. Ethyl-mercury is C2H5Hg, while methyl-mercury is CH3Hg. There is a slight yet critical difference, therefore, in the two different molecules.

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And it is methyl-mercury that has been shown to be the big danger in seafood. Methyl-mercury is the one that gets into your body and lingers there for ages and ages, gradually building up until it reaches that critical amount where it switches from being no problem to being a poison. Methyl-mercury is why they stopped using mercury thermometers, and why hat-makers used to go nuts.

But does a slight difference in chemical formula really make any difference? Does ethyl-mercury having one more carbon and two more hydrogen atoms than does methyl-mercury really matter? Yes, it does. In the same way that the difference between H20 (water) and H2O2 (hydrogen peroxide) matters. Would you rather drink a nice big cool glass of water on a hot day, or would you prefer to try to refresh yourself with a big gulp of hydrogen peroxide? A tiny difference in chemical formula can make a huge difference.

Nothing has ever shown ethyl-mercury to be dangerous in tiny amounts, which is something that can't be said for methyl-mercury. What's more, ethyl-mercury passes quickly through the body. It doesn't build up and linger for ages and ages, so you don't have to worry about the occasional tiny doses of it adding up to one big poisonous mass lurking somewhere inside of you. For the sake of safety, ethyl-mercury was held to the same safety guidelines as is its dangerous cousin methyl-mercury, yet the main reason for the latter being dangerous is that ability it has to accumulate. Which means that the safety regulations for ethyl-mercury have actually been as over-protective as requiring an asbestos-lined room, full fire-protection suit, and a fire brigade standing by every time you use your kitchen stove. There have been many tests conducted on the safety of the doses used in vaccines. There is absolutely no sign of ethyl-mercury being harmful in the amounts used in vaccines, either in the short term or in the long term. Unless you're a mold spore, that is. If you are a mold spore, then I strongly advise you to avoid thiomersal.

Also, consider the history of thiomersal. It has been being used in vaccines (and in all sorts of ointments and creams and whatever else) for over seventy years over seventy years. If anything, it is actually used in less items now than it has been. How, then, would it be responsible for a sudden rise in autism in the 1990's? If thiomersal was causing autism, then you'd expect for there to have suddenly been a huge number of autistic people roaming around starting in the 1940's, and for the number to have leveled off as the use of thiomersal leveled off.

In fact, the use of thiomersal has dropped considerably in the last few decades. Most vaccines don't use it anymore. Not because it was deemed unsafe, but because substitutes that are even more benign have been developed. If there was a link between autism and thiomersal, then we'd have seen the rates of autism drop in recent years. Which hasn't been the case.

For another example of the history of thiomersal use in relation to autism, we can look to the Danes. Half a million Danish children were tracked over many years. Some of them received vaccinations containing thiomersal. Some of them received vaccines that didn't contain thiomersal. And some were never vaccinated. If the thiomersal was causing autism, or even just increasing the chances of developing autism, then you'd expect for the proportion of autistic children in the thiomersal-vaccinated bunch to be higher than the proportion in the other two groups. If vaccines in general were linked to autism, then you'd expect for the unvaccinated group to have the least autistic children.

In the end, they discovered that there was no difference amongst the three groups. The levels of autism were the same. And this is about as large-scale as studies get.

Furthermore, suppose that the mercury atom in the molecule was poisoning the kids. Well, mercury poisoning is a well-known and well-studied ailment. People who are afflicted with mercury poisoning display certain characteristic symptoms. And those symptoms are nothing like autism:


Mercury poisoning symptoms
- - - - - - - - - -
- Peripheral nervous system damage, resulting in imagined burning or itching feelings
- Skin discolouration and loss
- Swelling
- Sweating
- Increased heart rate and blood pressure
- Drooling
- Loss of hair, teeth, and nails
- Sensitivity to light
- Weakness
- Kidney failure
- Insomnia
- Uncontrollable emotional outbursts
- Memory loss



That doesn't sound much like the typical symptoms of autism, now, does it?

It is a situation similar to that of MMR vaccines. There is absolutely no sign that thiomersal contributes in any way to autism, and quite a lot suggesting that there is no link at all. And unlike MMR vaccines, thiomersal isn't really even likely to be used in any vaccines today. So why would anybody avoid vaccines for fear of thiomersal causing autism in their children, especially given the huge and verified advantages that vaccines give to kids?

And notice that in the case of the MMR vaccines, it is the combining of three different viruses that is blamed for causing autism. While in the other case, it is mercury that is blamed. People who are blaming both for causing autism are blaming two totally completely utterly different mechanisms, about as different as they could be. If such disparate causes can cause autism, then probably just about anything would be able to cause autism.

In summary:

1) There is no shown link between MMR vaccines or thiomersal-containing vaccines and autism.
2) There are many studies showing a lack of any link between MMR vaccines or thiomersal-containing vaccines and autism.
3) Vaccines have a proven ability to prevent diseases.
4) Avoiding vaccines puts you at a much higher risk for catching avoidable diseases, and of suffering major permanent effects from the diseases.

Sunday, October 17, 2010

Cave Bacon!

As part of my quest to be the next Batman, I today decided to scout out a possible location for my very own Batcave. Thus, I planned an excursion and incursion to the famed Bridgeplace Caves. These are about twenty minutes south of where I live, on the outskirts of the towns of Bridgeplace.

Waaaaay back in The Olden Days, around the year 200,000,004 BC, there was a bunch of limestone. There was also a river. The river wanted to get from its start to its end as quickly as possible, because that tends to be the way of rivers. And so the river decided that the best way to accomplish its goal was to burrow its way through the limestone. In the process of doing so, the river managed to create a rather large series of caverns.

A little later on, back in The Less Olden Times, the local Native Americans discovered the opening into the caverns. The opening consisted of a hole in the ground about the size of the average pizza box (not that they are likely to have used that comparison themselves) that opened into a 200-foot drop straight down through a wide cave with absolutely no footholds or handholds, where you could see nothing but the occasional bat swooping around in the darkness and hear the occasional drip of water. Being human beings, they of course had to go in and poke at things.

They devised a series of ropes and logs and teleporter beams and whatnot that enabled them to reach the bottom with a fair margin of safety (though the remains of nineteen splattered native people at the bottom of the cavern indicates that it wasn't a sure thing). Exploring around, they found all manner of spiffy things. Chert protrusions, from which they could easily shape high-quality arrowheads. Gooey stuff on the walls, that was great for making body paint with (and which is still used by the world's cosmetic industry even today). Stalactites and stalagmites, that they would break off and wander around with to show off to people. A spring that produced about as pure a source of water as you could find in Nature. And a river flowing off into the darkness. Going upstream was a bit of a problem, since it would require being underwater for a significant amount of time. Going downstream was possible, however, and the natives found that the river exited through another opening about a mile and a half downstream.

The natives didn't really bother much with the cave most of the time, only making the occasional foray into it for chert and goo. Then the European settlers arrived, and the natives basically said, “Well, there goes the neighbourhood!” and tended to avoid the area. Until the 1770's, that is.

During the American Revolutionary War (aka “The War We Couldn't Really Be Bothered With And So Let The Colonials Win”), the British were a bit occupied elsewhere in the world and so couldn't really afford to have a proper number of British troops running around doing things. To help offset this lack, they enlisted a lot of the Native Americans to go out and burn crops or steal chickens or go cow-tipping or otherwise annoy those revolting rebels.

So when the native raiders came to the region of Bridgeplace, they remembered the caves. And they came up with a cunning plan. What they would do is to stage a quick raid on a farm or a small village, and then run away. But they wouldn't run too fast, because they wanted the militia and the angry farmers with guns to be able to follow them. The raiders would descend down the little hole into the caves, and the militia would say, “Ah ha! Forsooth, we have captured yon Rascals in yonder dank Hole! Let us make Camp here, and await their inevitable Re-emergence!” The militia would then sit around the hole in the ground, watching for the raiders to stick their heads out.

The raiders, meanwhile, would go down the underground river and sneak out through the secret opening there, whereupon they would go back to the farm or settlement and make a nice leisurely raid on it while all of its defenders were away.

It seems that they were able to pull this trick numerous times. Apparently the settlers had less of a “learning curve”, and more of a “learning horizontal line”.

Eventually things went downhill for all the native tribes in the region, and they were all relocated to the Midwest. The European settlers didn't really care about the mysterious hole in the ground and didn't poke around in it, and so the caverns were mostly forgotten about.

Then in the 1860's, a local farmer was digging a root-cellar about fifty yards south of the old cave entrance, which by then was lost amongst the bushes and brambles. The farmer got a bit of a surprise when at one point he stuck his shovel into the ground and the shovel just kept going. Investigating around a bit in the hole, he discovered that he'd broken through the roof of a massive underground chamber. And this time, there was a nice easy way to get down into the cave without having to depend on ropes and frantic scrambling.

And the farmer thought to himself, “Well, digging this root-cellar went a lot faster than I thought it would!”, and he then proceeded to drag all of his roots down there for storage. And all of his neighbours' roots for storage, too, for a small fee. There was probably enough space down there to store the entire state's root supply, and the climate down in his new root-cellar remained at a constant low temperature (about 60°F) all day and all night, all year.

For the next eighty years, the caves served as the farm's root-cellar without much other ado. In the 1920's somebody put in some pipes to bring the water up from the cave's spring and to the house above, but that was about it. Nobody really looked around down there, or took much notice of what was down there unless it involved the storage of root crops.

In the late 1940's, the land finally changed hands. And with the land went the root-cellar under the land. The new owner envisioned a bit more than simply storing turnips, however. He decided that the best thing to do was to open the caves up for the public. Which is exactly what he did. He installed stairs and electric lighting where needed, built a rather silly looking visitor's center, and then waited for the tourists to show up. Which they did.

And not just tourists, either. One of the local mayors decided to hold all official town meetings in one of the bigger rooms in the cavern. For one thing, it was nice and cool down there. Also, the acoustics were excellent. And best of all, it made it easier to kick out people whom he grew annoyed with.

Today there are no more town meetings down there, but there are still a large number of tourists who venture down to brave the perils of the bats and the dreaded cave crickets.

This is the Visitor's Center in all its 1950's glory, complete with wonderfully awful fake stone and log walls:

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Here is how things look above the caves:

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There are lots of rocks sticking up through the soil:

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There is also a little sluice system there for herds of tourist children (or childish adults) to use in searching through mud for various treasures:

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While the sea may have the sea-urchin, here in the mountains we have the less known but the far more dangerous mountain-urchin. No relation to the mountain oyster.

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The original cave opening:

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The root-cellar opening, and Stalwart Tourguide Guy:

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Stalwart Tourguide Guy was an interesting fellow. Quite nice and friendly, though he'd obviously gone through his whole spiel at least a jillion times and is a bit bored by it. You could tell when he was repeating his memorised bits and when he was actually conversing, because during the bits he was reciting he would pronounce each and every syllable as a separate word. And sometimes each syllable as two separate words, which is a neat trick.

And then we went into the caves and looked around. A lot of the photos from inside are a bit grainy or blurry; this is because, even with all of the electric lighting inside, it was still rather dark in there. And since I didn't want to use the camera flash and traumatise our little batty friends (who were lurking everywhere in the shadows), I had to use a long shutter time.

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This formation is called The Wedding Cake. In part because it looks vaguely like a wedding cake, but mainly because there have been at least fourteen weddings held beside it:

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Right next to it is Lovers' Leap. The tradition is that a loving couple is supposed to hold hands and leap off the uppermost ledge. If they really do love each other, then they'll safely land on the floor of the cavern about sixty feet below (yeah). If one or both of them doesn't really love the other, however, then they'll smash into a second ledge that's about halfway down and be splattered all over the place. I'm not aware of anybody who has ever put this to the test, though.


More cave stuff. To put things a bit in scale, keep in mind that the roofs of many of these caverns are about 100 to 180 feet high.

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Aaaaaaaaaaa! Giant jellyfish!

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And last but not least: cave bacon!

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In the end, despite the easy availability of bacon and of giant crayfish and of crickets that I could potentially train to be my minions, I decided not to establish my Batcave there. The bats had already done so, and thus it would be too redundant. And so I went home.