The year 1900 marks the birth of an organization that now plays a prominent role in British politics — the UK Labor Party. Their first manifesto is a curious document. Read about a quarter way down the page and you find a campaign promise that sounds all too familiar: “No Compulsory Vaccination”. Strange as it seems, in 1900 the Labor Party promised voters they would end mandatory vaccination against smallpox.
They failed, of course; and it’s a good thing, too. Had they succeeded, smallpox would probably be going the rounds even now. But the Labor Party’s short-lived crusade against vaccines illustrates a surprising point: anti-vaccine movements are almost as old as vaccination itself.
Check out this wonderful cartoon (from the American Memory pages at the Library of Congress). It was done shortly after Edward Jenner introduced his smallpox vaccine. The artist seems to imply that infecting people with cowpox will make them turn into cows, or at least sprout cow-like appendages. As the cartoon illustrates, the smallpox vaccine aroused considerable controversy at various times in the 19th century — ironic, given the smallpox vaccine arguably saved more lives than any other medical intervention in history.
Opposition to vaccination hasn’t died away with smallpox, of course. As a quick search on Google will demonstrate, it’s alive and doing better than ever. Modern opponents remain just as hostile to vaccination as their 19th-century forbearers, although they no longer seem especially worried about their children turning into farm animals. Nowadays they make other arguments instead.
The most determined and capable anti-vaccine group in existence today is the National Vaccine Information Center(NVIC). When I type “vaccine” into Google, the NVIC actually shows up on the first page of results. You can get a feel for the kind of information the NVIC offers from a brief trawl through their website, which turns up pages like this one by a Dr. Julian Whitaker, apparently a practitioner of alternative medicine:
Any doctor who assures patients that vaccines are completely safe is flat-out lying…Depending upon which vaccine is being administered, a single shot can contain a brew of adulterated bacteria, viruses, aluminum, mercury, formaldehyde, hydrochloric acid, and/or numerous multisyllabic chemical additives. To say that repeated exposures to such a wide range of toxins have no cumulative adverse effects on a child’s developing nervous and immune systems is more than irrational—it’s diabolical.
This paragraph — like the remainder of the NVIC website — is a noxious brew of fallacies and misinformation. Unfortunately, it’s misinformation of a particularly insidious kind, which is why these same arguments are repeated so often on anti-vaccine websites. The CDC has a list of the ingredients and reagents pharma companies use to manufacture vaccines at this link, and compounds like formaldehyde, thimerosal and various aluminum salts do indeed appear on it. Their presence here, however, is by no means so ominous as the NVIC would like you to think. To understand why, we have to think for a minute about how and why we make a vaccine.
We said in a previous post that Nature crafts poisons more terrible than any chemists can devise. One of the best examples of Nature’s murderous skill is the diphtheria toxin. Cyanide is a clumsy and inefficient killer compared with this intricate molecular machine.
The diphtheria toxin gets into your cells by sticking to a molecule on the cell surface, tricking the cell into treating it as legitimate cargo. Once inside, it gets broken up into pieces; one of these fragments catalyzes a reaction that shuts down protein synthesis, bringing the cell’s normal operations to a grinding halt. Strains of C. diphtheriae that produce the toxin cause the disease called diphtheria. The Spanish dubbed it “El Garrotillo”, The Strangler, on account of the way it often kills children. As recently as the 1920s, it caused 13-15,000 deaths in the US each year.
We can fight diphtheria by taking advantage of your immune system’s built-in memory capability. The immune system has a remarkable ability to remember invaders it’s encountered previously. When it meets the same enemy a second time, it mounts a devastating response that prevents the invader from gaining a foothold again. If we can introduce your immune system to the diphtheria toxin, it can destroy the invaders before they make it past the shoreline, and this is the basic idea behind all vaccines.
It sounds nice in theory; but how can you arrange for your immune system and diphtheria toxin to meet? If I just inject you with straight diphtheria toxin, it would kill you rapidly. What we need is a way to inactivate the protein — to damage it so it becomes harmless. That’s why we treat diphtheria toxin with formaldehyde.
Formaldehyde is a much simpler and smaller molecule than diphtheria toxin — just one carbon atom, two hydrogens and an oxygen. Oxygen is more electronegative than carbon, meaning it tends to hog the electrons they share (think of it as an unusually selfish spouse). The oxygen is double-bonded to the carbon, so the carbon ends up very electron-poor, and the two wimpy hydrogens aren’t much help. So formaldehyde tends to act as an electrophile, an electron-poor molecule looking for love in all the wrong places. When you treat diphtheria toxin with formaldehyde, it reacts with relatively electron-rich nitrogen atoms in the protein, crippling it in a way that makes it harmless. Formaldehyde-treated diphtheria toxin is inactivated — it can no longer get inside your cells and shut them down. Your immune system, however, can recognize the inactivated protein and remember it for future reference.
Treating diphtheria toxin with formaldehyde is a clever solution to the problem, and in fact we inactivate tetanus toxin in the same way. We have to be a little careful, however, because the same reactive nature that makes formaldehyde useful also makes it potentially dangerous. It can react with proteins and DNA in your cells in just the same way it reacted with the diphtheria toxin. So formaldehyde is diluted during the manufacturing process, and the remaining quantity in the finished vaccine is less than 100 micrograms (100 millionths of a gram) per dose.
Formaldehyde in a vaccine might sound unnerving. Isn’t formaldehyde a toxic chemical? But toxicity is a more slippery concept than popular culture would have you believe. (See my earlier post, “What Does ‘Toxic’ Really Mean?”) When we talk about toxicity, there’s a number of things we have to think about — how does your body metabolize the compound, how quickly is it excreted, and how much is too much? There’s an old saying that “the dose makes the poison”, and it’s certainly true in this case, because small quantities of formaldehyde are being generated by ongoing processes in your body right now.
Your blood and tissues have a natural concentration of about 2.5 micrograms (millionths of a gram) of formaldehyde per milliliter. If you do the numbers, it turns out that a newborn baby’s bloodstream has over 10 times more formaldehyde than a vaccine at any given time. Moreover, your body metabolizes formaldehyde rather quickly, converting it to formic acid and either excreting the formic acid in your urine or converting it to carbon dioxide. The tiny quantity of formaldehyde in a vaccine doesn’t hang around for very long.
At higher doses, formaldehyde can indeed be quite dangerous, but the amount you have in vaccines like DTaP simply isn’t large enough to be a problem. It’s a tiny fraction of the amount your body already generates and breaks down as a matter of course. Foods like meat and fruits naturally contain small quantities of formaldehyde and/or compounds your body converts to formaldehyde anyway, so your diet exposes you to far more significant quantities of formaldehyde than you get from a vaccine.
Aluminum & Acid
Dr. Whitaker also mentions hydrochloric acid as a “toxin” of concern. It’s an unfortunate argument, because it strongly suggests he’s being disingenuous. Either that, or he somehow skated through college and medical school while flunking general chemistry. Let me explain what he forgot to tell his readers — and I’ll keep it as simple as possible, so even Dr. Whitaker can follow along.
Hydrogen chloride is a simple molecule — a hydrogen atom stuck to a chlorine. When you put it in water it separates into a hydrogen ion* and a chloride ion. pH is a measure of hydrogen ion concentration; lower numbers mean more hydrogen ions and hence a more acidic solution. If I mix hydrochloric acid with a base, the base and the acid react and I end up with water and a salt. Mixing equal amounts of sodium hydroxide and hydrochloric acid, for example, gives me water and sodium chloride.
Imagine for a minute we have a public swimming pool with a pH that’s too high(i.e. too basic). Swimming pool pH needs to stay between 7.2 and 7.6, so you might add a little hydrochloric acid (aka muriatic acid) to bring the pH back down into the right range. Once you put it in the pool, the hydrochloric acid reacts with some of the excess base to make water and salt and you reduce the pH. The same is true when we use hydrochloric acid to adjust the pH of a solution in the lab, as for example when we manufacture a vaccine. The only thing that makes hydrochloric acid dangerous is the low pH of a hydrochloric acid solution. If you’ve mixed the hydrochloric acid with base and brought it back to a neutral pH, however, it is in no way dangerous — no more so than a glass of water with some table salt in it.
The aluminum salts play a much more interesting role. Manufacturers add salts like aluminum hydroxide to certain vaccines because they make vaccines more effective — you get a much more significant response to the vaccine. We’re not completely sure why that happens, although we have some theories about it. We do know, however, that you and I are exposed to plenty of aluminum as part of everyday life.
Aluminum is the third most abundant element in the Earth’s crust; it’s abundant in many types of soils, especially soils rich in clay. You consume small quantities of aluminum in the food you eat, and human breast milk contains aluminum on the order of ~40 micrograms per liter. Although aluminum can be dangerous in very high doses, any compound can be dangerous if you take too much, and there’s no reason to believe aluminum is dangerous at the level present in a vaccine, which are measured in fractions of a milligram.
Which brings us at last to the most controversial additive on Dr. Whitaker’s list: thimerosal. Its use in vaccines dates to the 1930s, and it was prompted by a series of nasty accidents with multi-dose vaccine vials. By sticking the needle through the rubber septum on the vial multiple times, nurses and/or doctors sometimes introduced bacteria by accident, and some children were inoculated with vaccines from Staph-contaminated vials. To avoid these lethal accidents, vaccine manufacturers began incorporating thimerosal as a preservative in multi-dose vials back in the 1930s, and starting in 1968 preservatives were required in multi-dose vials by law.
It’s worth pointing out that the guidelines for the amounts of thimerosal in vaccines were based on methylmercury, even though thimerosal breaks down to ethylmercury in the body, and ethylmercury is excreted much more rapidly than its infamous cousin. (Nearly all fish and seafood contains traces of methylmercury, by the by. Indeed, seawater itself contains mercury, albeit at extremely low concentrations.) Nor is there any evidence to suggest thimerosal was dangerous at the levels found in vaccines.
At present, however, the safety of thimerosal is a moot point, because thimerosal has been removed from pediatric vaccines as a precautionary measure. Currently there are no pediatric vaccines on the routine schedule that are manufactured with thimerosal as a preservative. Indeed, this has actually been true for some years now. The MMR vaccine does not and never did contain thimerosal. Some vaccines like influenza vaccine contain thimerosal, but there is a limited supply of thimerosal-free influenza vaccine available for patients who so prefer.
Given what we know about how vaccines are made, why do opponents continue to talk about “toxic chemicals” in vaccines? And this is perhaps the most interesting question of all. We can understand why vaccines might have aroused controversy in the early 19th century. After all, Jenner himself didn’t know for certain why vaccination worked; he merely knew from experiment that it did. Today, however, we know much more about immunology than any of Jenner’s contemporaries. So why do vaccines elicit so much hostility? This part is just my opinion, but I think there are three different forces at work.
*The hydrogen ion actually gets picked up by a water molecule to make H3O+, the hydronium ion, but it’s the same general idea.
The first issue is greed, pure and simple. It’s ironic that alternative medicine practitioners often condemn the greed of the pharmaceutical industry, because many of them are just as money-hungry as the industry they criticize. Pharma companies have unquestionably engaged in dubious or even dishonest marketing practices at times (my favorite example is ghostwriting). At the end of the day, however, pharma companies cannot market a medication unless it has first been approved by the FDA, and the FDA regulations are the safeguard we have to punish them when they get out of line.
When it comes to Dr. Whitaker and his ilk, by contrast, we have no such safeguard. Dr. Whitaker sells supplements that are regulated by much looser guidelines. He can make all kinds of vague, untested claims about his supplements so long as he tacks on the usual warning:
“These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.”
Dr. Whitaker, Dr. Mercola and other supplement-sellers stand to make money off the anxieties of patients and parents — and that’s why they spread this kind of misinformation. It’s unfortunate, but these people are greedy and unregulated, and it’s what they do.
I think the second factor responsible for public hostility is the media. We’ve all heard about the whole Wakefield-autism-vaccine controversy, which began with a single deeply flawed study published in the Lancet back in 1998. Now here’s the interesting question. Would you or I ever have heard of this study if it hadn’t been for science & health reporters? Of course not. Many thousands of scientific studies are published each year, and most of us don’t read The Lancet.
The media took Wakefield and made him into a public figure. I assume they did it because it was a sensational stories and many reporters can be surprisingly gullible. Journalists are supposed to be people who ask tough questions; yet out of the many hundreds of journalists who covered this story at one time or another, how many of them thought to question Dr. Wakefield’s motivations? Only one: Brian Deer.
Over the past few years the media has definitely come around, of course. Most articles you see on vaccines nowadays emphasize their safety. Even these articles, however, suffer from a critical defect. All too often, reporters explain science & health issues by not explaining them. In other words, they’ll tell you “Dr. X says toasted spam is good for you,” but they won’t tell you why Dr. X thinks toasted spam is good. Detail-free reporting of this kind leaves the field wide open for people like Dr. Whitaker to win converts with misleading arguments.
The final reason why vaccines are controversial, however, is the most interesting one. To my mind, vaccines are actually victims of their own success. Vaccines have done an incredible job of eradicating diseases that once killed or crippled thousands or millions of people. Neither you nor I know anyone whose child perished at the hands of El Garrotillo. Neither you nor I can remember acquaintances who were crippled by polio or died of smallpox. Around the world, tens of thousands of babies die of neonatal tetanus or lockjaw every year, but it doesn’t happen in the US, so we don’t think about it. We take what we have for granted; we assume it was always this way.
Many people apparently see vaccines as “unnatural”, and we forget there’s nothing so natural as infectious disease. When we battle bacteria like C. diphtheriae, our enemy is none other than Nature itself. Vaccines are the most effective weapon we’ve found in what would otherwise be an unwinnable war. It would be a shame to let complacency, media gullibility and the avarice of quacks betray us into unnecessary defeat.
Incidentally, there’s a really nice summary of the evidence on vaccines and autism at this link, by Jeffrey Gerber and Paul Offit. It isn’t behind a paywall; it’s free to access, the way all scientific literature should be.
 FDA: Thimerosal in Vaccines.
 Paul Offit and Rita Jew. “Addressing Parents’ Concerns: Do Vaccines Contain Harmful Preservatives, Adjuvants, Additives or Residuals?” Pediatrics December 1 2003: 112(6), 1394-1397.
 Karen Broder, Margaret Cortese et al. “Preventing Tetanus, Diphtheria, and Pertussis Among Adolescents: Use of Tetanus Toxoid, Reduced Diphtheria Toxoid and Acellular Pertussis Vaccines.” Centers for Disease Control: March 24, 2006.
 Agency for Toxic Substances and Disease Registry: Aluminum, Relevance to Public Health.
 Sundeep Dhareshwar, Valentino Stella. “Your Prodrug Releases Formaldehyde: Should You Be Concerned? No!” Journal of Pharmaceutical Sciences October 2008: 97(10), 4184-4193.
Dhareshwar, S., & Stella, V. (2008). Your prodrug releases formaldehyde: Should you be concerned? No! Journal of Pharmaceutical Sciences, 97 (10), 4184-4193 DOI: 10.1002/jps.21319