Offit: 10,000 vaccines
10,000 vaccines
The Quote
"Pediatrics", Special Article, "Addressing Parents’ Concerns: Do Multiple Vaccines Overwhelm or Weaken the Infant’s Immune System?"
Link: [[1]]
The relevant section is below, with the quote highlighted:
DO VACCINES “OVERWHELM” THE IMMUNE SYSTEM?
Infants Have the Capacity to Respond to an Enormous Number of Antigens
Studies on the diversity of antigen receptors indicate that the immune system has the capacity to respond to extremely large numbers of antigens. Current data suggest that the theoretical capacity determined by diversity of antibody variable gene regions would allow for as many as 10^9 to 10^11 different antibody specificities. But this prediction is limited by the number of circulating B cells and the likely redundancy of antibodies generated by an individual.
A more practical way to determine the diversity of the immune response would be to estimate the number of vaccines to which a child could respond at one time. If we assume that 1) approximately 10 ng/mL of antibody is likely to be an effective concentration of antibody per epitope (an immunologically distinct region of a protein or polysaccharide), 2) generation of 10 ng/mL requires approximately 103 B-cells per mL, 3) a single B-cell clone takes about 1 week to reach the 10^3 progeny B-cells required to secrete 10 ng/mL of antibody (therefore, vaccine-epitope-specific immune responses found about 1 week after immunization can be generated initially from a single B-cell clone per mL), 4) each vaccine contains approximately 100 antigens and 10 epitopes per antigen (ie, 10^3 epitopes), and 5) approximately 10^7 B cells are present per mL of circulating blood, then each infant would have the theoretical capacity to respond to about 10,000 vaccines at any one time (obtained by dividing 10^7 B cells per mL by 10^3 epitopes per vaccine).
Of course, most vaccines contain far fewer than 100 antigens (for example, the hepatitis B, diphtheria, and tetanus vaccines each contain 1 antigen), so the estimated number of vaccines to which a child could respond is conservative. But using this estimate, we would predict that if 11 vaccines were given to infants at one time, then about 0.1% of the immune system would be “used up.”
However, because naive B- and T-cells are constantly replenished, a vaccine never really “uses up” a fraction of the immune system. For example, studies of T-cell population dynamics in HIV-infected patients indicate that the human T-cell compartment is highly productive. Specifically, the immune system has the ability to replenish about 2 billion CD4+ T lymphocytes each day. Although this replacement activity is most likely much higher than needed for the normal (and as yet unknown) CD4+ T-cell turnover rate, it illustrates the enormous capacity of the immune system to generate lymphocytes as needed.
Offit On The Quote
"An Epidemic of Fear: How Panicked Parents Skipping Shots Endangers Us All", Wired Nov09, Amy Wallace, 19Oct2009 [[2]]
A while back, Offit was asked to help put together a reference text on vaccines. Specifically, his colleagues wanted him to write a chapter that assessed the capacity of the human immune system. It was a hypothetical exercise: What was the maximum number of vaccines that a person could handle? The point was to arm doctors with information that could reassure parents. Offit set out to determine two factors: how many B cells, which make antibodies, a person has in a milliliter of blood and how many different epitopes, the part of a bacterium or virus that is recognized by the immune system, there are in a vaccine. Then, he came up with a rough estimate: a person could handle 100,000 vaccines — or up to 10,000 vaccines at once. Currently the most vaccines children receive at any one time is five.
He also published his findings in Pediatrics. Soon, the number was attached to Offit like a scarlet letter. “The 100,000 number makes me sound like a madman. Because that’s the image: 100,000 shots sticking out of you. It’s an awful image,” Offit says. “Many people — including people who are on my side — have criticized me for that. But I was naive. In that article, I was being asked the quesion and that is the answer to the question.”
How Bad Is The Quote?
My own view is that, in isolation, it doesn't mean anything at all.
But might do it was one of many examples of statements with comparable weaknesses.
Really how you view the quote depends on how you view Offit.
Here The Hatred Scale comes in handy:
(0) X is a saint. If you disagree you are a devil.
(1) X is a good person and by default I trust everything they say.
(2) X may have good intentions but their rhetoric sits uneasily with their pretensions to be a medical authority.
I wonder about thier judgement more generally.
(3) X may have started out with good intentions but is now compromised by special interests etc.
I don't take X's assertions at face value.
(4) X is knowingly corrupt and by default I distrust everything they say.
(5) X is a devil. If you disagree you are a devil.
Obviously how you interpret quotes of Offit's such as the "10,000 vaccines" will depend heavily on where you sit on the Hatred Scale with Offit.
I sit at (1) - I don't believe in saints. I can imagine (2) perfectly well, (3) with some difficultly and (4) just seems very unlikely.
What does effect does the "10,000" vaccines quote have on me?
For someone in my position, the quote is correct as far as it goes, but it is impossible to deny that it is susceptible to misuse by stripping it of the surrounding context, whether this is done by misguided friends or by opponents of Offit. The same point could have been put perfectly well without this vulnerability, as Offit himself acknowledges.
So the quote *could* help support a move to (2), if it was established that it was part of a pattern of quotes that offer similar hostages to fortune - whether being minor factual slips, bogus argument, vulnerability to misquoting, etc. The more such quotes you make, the sloppier you are being. Past a certain point, you are not a medical authority, fastidious about scientific authority, but instead a polemicist.
[There is nothing wrong with being a polemicist in itself, but there is something wrong with asserting disinterested medical authority at the same time as being a polemicist. Moving to (2) thus does prepare the way for a later move to (3) becuase it casts questions over character and quality of judgement.]
But the quote could instead provide evidence that I should stay at (1), if it is overly relied on by Offit's opponents as a conclusive, stand-alone clincher that Offit has a habit of sloppy rhetoric. This is because, given my current worldview, the quote does not come close to supporting that conclusion if you just consider it in isolation.
I think that someone who presents the quote with repeated insistence that it should by itself change Offit's level on my Hatred Scale is conveying information. But the information is not about Offit, but about how they view Offit - the more they do this, the closer they appear to (4) - or possibly even (5).
Summary
Taken in context, the quote is very clearly conveying "an order-of-magnitude estimate of an upper safety limit derived from theoretical principles" rather than "a theory that it is safe for babies to receive 10,000 vaccines at once" - the latter being the gloss typically given by Offit's opponents.
However that latter interpretation, with its mixture of arrogance, ignorance and carelessness, dovetails with the extremely negative view of Offit's moral makeup that is a component of many vaccine sceptic world views, and so it has gained a great deal of currency in the vaccine sceptic community - to the point where many have the sincerely and deeply held conviction that no alternative interpretation is possible by an objective observer acting in good faith.
It doesn't help that there are definitely some aspects of vaccines that don't scale up by 10,000 or anything close - eg aluminium levels.
As a consequence, use of the quote carries a lot of information - not about Offit, but about the attitude of the quoter to Offit. If someone seriously believes the anti-Offit interpreration of the quote, it's a very strong indicator that they will tend to frame any issue involving Offit primarily in terms of Offit's moral turpitude, and will show great reluctatnce to engage with any evidence that points in any another direction. This means that it is very unlikely they will be able to have a fruitful discussion about issues involving Offit with anyone who does not have a similarly low opinion of him.
Note that an inability to treat issues involving Offit objectively does not imply an inability to deal with other issues around vaccines objectively. Offit is a vaccine researcher, directly profits from vaccines, and writes and campaigns vigourously for the CDC and general establishment view on vaccines. This makes him a lightning rod for vaccine scepticism on a number of fronts and so attitudes towards him are often very extreme. Unfortunately it also means he can come into vaccine discussion via a number of routes.
The ease with which the quote can be taken out of context demonstrates how careful you need to be about how you phrase your arguments when debating with opponents who distrust your motives so fundamentally.