Aluminum safety and vaccines
Some asked me about the risk of aluminum in vaccines, so I thought that would be a worthwhile question to address.
In addition to the substance against which a patient is being immunized, some vaccines contain adjuvants. An adjuvant is an additional substance that is used to boost the effectiveness of the vaccine. This has several benefits:
- the immunity may be longer-lasting, reducing or eliminating the need for more vaccine doses
- the immunity may be more effective, meaning that a greater proportion of those vaccinated will respond
- the vaccine can get away with using less of the bacteria/virus against which you are being vaccinated
One adjuvant that used to be used was thimerosol, which is now only found in the annual influenza vaccine. It was removed as a precautionary measure, even though there is no evidence it causes harm, and a number of studies which failed to find any evidence of harm.
The vast majority of North American vaccines use aluminum salts (and aside from influenza, these are the only adjuvants used in Canada).
The three salts used are:
- Aluminum hydroxide
- Aluminum phosphate
- Potassium aluminum sulfate
These have been used for seventy years in vaccines (since 1926), so they have a long track record of safety.
The World Health Organization and European standards bodies recommend (and Health Canada agrees) that no dose of vaccine contain more that 1.25 mg per dose of human vaccine).
Let’s put that dose in context. Aluminum is a very common substance in our environment. Even human breast milk, for example, contain 0.040 mg/L; commercial formulas have 0.225 mg/L. So, in about 31 litres (8 gallons of breast milk) you get as much aluminum as one vaccine dose (or 5.5 L of formula).
Doing the math
Let’s be conservative, and assume a breast-fed baby eats 6 times a day (every 4 hours, which as any new mom will tell you, is a relatively reasonable assumption). That means they’ll drink an average of 125 mL (5 oz) of breast milk every feeding, or 6 x 125 mL = 750 mL per 24 hours. Thus, with even fairly conservative assumptions, every 40 days or so, an exclusively breast-fed baby will eat as much aluminum as in one vaccine dose.
If, on the other hand, the baby is formula fed, at the same volume and rate, then the child ingests that much aluminum every 8 days or so.
Put another way, under US guidelines (and I expect Canadian ones are almost the same) within the first 6 months of life, a child would get a total of 4 mg of aluminum from vaccines. They would have absorbed 10 mg from breast milk, 40 mg from formula, or 120 mg from soy formula.
What happens to the aluminum?
Now, maybe there’s a difference between injecting aluminum and eating it? As it turns out, not that much.
Less than 1% of the aluminum consumed by mouth enters the bloodstream—it is quickly bound to a protein called transferrin (also involved in iron metabolism) and excreted through the kidneys.
Almost all the aluminum injected by vaccines will enter the bloodstream. But, there again it binds to transferrin, and is removed by the kidneys. How fast? Regardless of oral or injection route:
- 50% gone within 24 hours
- 75% gone within 2 weeks
- Almost 100% gone within 3 years.
By adulthood, we have accumulated 50-100 mg of aluminum in the body. That gives you some idea of how rapidly you’re excreting it—40 mg of infant formula in the first 6 months is almost equivalent to the total aluminum that remains in the body by adulthood. Clearly, the vast majority is not sticking around.
We don’t have to rely on theory to prove this. All unvaccinated babies have 5 nanograms of aluminum per mL of blood all the time. If you vaccinate a baby, the concentration of blood aluminum doesn’t change enough for us to detect it. We’re talking about such tiny, undetectable increases that it would be incredible for it to cause a problem.
Are you saying aluminum can never be harmful?
No, of course not. With everything, “the dose makes the poison.” Even water is poisonous and potentially fatal at high enough doses.
Premature babies in NICUs can have aluminum troubles if their kidneys don’t work (remember, aluminum is excreted by the kidneys—no kidneys, and all that aluminum sticks around).
The second group is (you guessed it) adults with renal failure. If they take antacids, these can cause problems, since a daily dose of antacids contains about 1,000x the dose of aluminum in a vaccine. And even here it takes months or years of high-dose aluminum administration to cause problems.
Premature infants or patients with kidney failure have blood levels of aluminum at least 100x greater than healthy babies. And, remember, healthy babies’ blood level of aluminum doesn’t even budge when we vaccinate.
And, like anything, the immune reaction we’re trying to generation with aluminum can cause local soreness or redness, or rarely an allergic-type reaction. But, those are usually minor issues.
So, harm from this miniscule amount of aluminum (which is in our food and drinking water anyway, at higher levels) is extraordinarily unlikely.
Furthermore, we’ve used the stuff for seven decades, without a huge outbreak of problems from aluminum toxicity, which effects are well known from patients with renal failure.
But, we have even more cause for confidence. In 2004, an aluminum containing vaccine and adverse reactions was reviewed. This included 3 randomized trials, 4 semi-randomized studies, a cohort (retrospective) study, and 27 other studies.
[Note that this study was done in the UK, where the American/Canadian element aluminum is called aluminium, but it’s the exact same thing, just in the Queen’s English.]
Two main groups were compared:
- Children vaccinated with aluminum hydroxide adjuvants vs. no adjuvants
- Children vaccinated with various aluminum adjuvants vs. no adjuvants
Aluminum adjuvants caused more local pain or swelling—but, this is to be expected, because the whole reason we include adjuvants is to create a more robust immune response from the body. There was no difference in the rate of more serious adverse reactions:
The frequencies of local reactions of all types, collapse or convulsions, and persistent crying or screaming did not differ between the two cohorts of the trials. In older children, there was no association between exposure to aluminium-containing vaccines and onset of (local) induration, swelling, or a raised temperature, but there was an association with local pain lasting up to 14 days (2·05 [1·25–3·38]).
And, most importantly,
We found no evidence that aluminium salts in vaccines cause any serious or long-lasting adverse events.
Critics of vaccines will sometimes appeal to studies on mice or local reactions about the problems associated with aluminum injection. However, why rely on mice studies when we have decades of human evidence and experience that strongly suggest safety in the real human world?
(There’s an old joke in medical research that we can cure every cancer in mice—it’s shifting the treatment to humans that’s the trick.)
And, it should be remembered too—everyone in public health, in vaccine research, and government health groups puts their money where their mouth is. They get vaccinated. Their children get vaccinated. It seems a real stretch to claim that these people—who often dedicate their whole lives to children’s health—are part of a conspiracy to ignore data about the safety of children. Especially when those at risk includes them and their children.
Conclusion: What choices do we have?
Let’s imagine for a moment that the critics get their way—we stop using aluminum in vaccines.
Fine. What do we do then? We have, it seems to me, three options:
- Vaccinate without adjuvants—this would require more frequent dosing of vaccines, would risk a loss of immunity over time (setting us up for outbreaks), or perhaps using higher concentrations of bacterial/viral material we’re trying to vaccinate against. Can we be sure that this would not create greater problems? Might not critics then start to complain about the “high doses” used, or the “increased frequency”? More vaccines more often would mean higher costs and a higher risk of outbreaks, since people would be more likely to miss their shots.
- Vaccinate with new adjuvants—perhaps we could develop new adjuvants (like thimerosol). But, this is unlikely to satisfy the critics for long. Even if a new adjuvant had no evidence of harm, they would still complain: and they do just that about thimerosol, even when removing it doesn’t solve the problem they claim it caused. We have decades of safety and confidence with aluminum salts, and wouldn’t have evidence that strong for decades (if ever) for another adjuvant. So, we’d be stuck in the same situation we are now, only with less evidence.
- Stop vaccinating altogether—this seems to be what most critics want, and what they tend to choose for their children. But, that option is a fool’s errand. We know what happens when vaccination lapses, and we know from sorrowful historical experience how devastating these diseases are.
So, which do we pick? One of the three options above?
Options #1 and #2 seem to me to put us exactly where we are now, but with less evidence, more cost, and potentially less effectiveness of our vaccine programs. Not much of a deal.
Option #3 is madness. Even vaccine critics would realize that if the majority of the population wasn’t smart enough to ignore them. It only takes a couple of polio outbreaks to see the light. (With effort, polio may soon become the second disease after smallpox to be utterly eradicated by vaccination.)
(Iron lungs on a polio ward, New York, 1916).
Or, do we rely for now on seven decades of experience and studies—and pretty convincing evidence from the dose data—that nothing ominous is going on?
I—and every public health group on the planet—would recommend the latter.