No, childhood vaccines will not be “made from human tumors”

hela-iismall

Every so often there’s an article that starts making the rounds on social media, in particular Facebook and Twitter, that cries out for a treatment by yours truly. Actually, there are more such articles that are constantly circulating on social media that I could work full time blogging and still not cover them all. So I’m stuck picking and choosing ones that either (1) particularly pique my interest; (2) irritate me enough to goad me into action; or (3) reach a level of ubiquity that I can no longer ignore them. I don’t think this one’s hit #3 yet, but it certainly scores on #1 and #2. Who knows? Given time, it might make #3 too, in which case a pre-emptive strike at its nonsense is definitely warranted.

I’m referring to a post on the always cranky, always misinformation-packed VacTruth.com, a website that seems to be vying to replace Age of Autism as the most wretched hive of antivaccine scum and quackery on the Internet now that AoA appears to be recycling a lot of posts for December. (One wonders if the editors are running out of writers there.) This time around, it’s an article by someone named Sandy Lunoe entitled Vaccines Will be Made from Human Cancer Tumors.

Whoa. Sounds really, really scary, doesn’t it?

First off, the title alone is deceptive. It’s the very same gambit as the “human fetal tissue in vaccines” gambit. Just as it’s not actual human fetal tissue being used to make vaccines but rather cell lines derived from a human fetus over 40 years ago, what is being proposed here is not to make vaccines out of actual human tumors but to use human tumor cell lines; i.e., cell lines derived from human tumors many years ago. Before I discuss what the FDA really discussed and did, let’s take a look at Lunoe’s fear mongering take on the FDA hearing of September 19, 2012:

Unbelievably, the method of producing vaccines using cells that are derived directly from human cancer tumors has been approved even though the vaccines may induce cancer in recipients. This method is cheaper and faster than breeding animals for the culture media – and human cancer tumors are readily available.

At a meeting of the Food and Drug Administration (FDA) in September 2012, the discussion which led to approval was no less than a scandal. [1]

The health authorities and vaccine manufacturers blatantly revealed their uncertainty regarding the safety of vaccines made from cancer tumors. Some of the incredible statements from the meeting are quoted directly. A more detailed account is given in this article, with statements directly quoted from the meeting in italics. [2]

Not surprisingly, how those statements are “directly quoted” reveals cherry picking and deception. For instance, let’s look at the first statement from the hearing:

We have really identified three major factors that could potentially convey risk from tumor derived cells. And these include the cells themselves … and if they were tumor-derived cells then maybe they themselves could form tumors in a vaccine recipient. (Dr. K)

Now let’s look at the statement in context:

We have really identified three major factors that could potentially convey risk from tumor derived cells. And these include the cells themselves. And of course, if cells were present in vaccine, they could retain their original phenotype.

And if they were tumor-derived cells then maybe they themselves could form tumors in a vaccine recipient. Although they would still be susceptible to rejection by the host immune system, and so it is unlikely that that would be a problem. But nonetheless, that is a theoretical concern.

Notice the clever use of the ellipse and how Lunoe left out the qualifications made by Phil Krause, Acting Deputy Director of the Office of Vaccines at the time, that this was a theoretical concern. The fact is that the human cancer cell lines don’t generally form tumors in humans. They just don’t. As Dr. Krause noted, leaving aside the fact that if any intact human cells were to remain in a vaccine product after manufacture they would be highly unlikely to be viable given the chemicals used to inactivate the viruses used (such as formaldehyde), the likelihood of a cell or handful of cells forming a viable tumor in a human muscle (which is where they would find themselves given that most vaccines are injected intramuscularly), much less going beyond that and metastasizing, are minuscule to zero. I’ve worked extensively with human tumor cell lines; I know them. I’m familiar with them, at least breast cancer, melanoma, and prostate cancer cell lines.

Moreover, it’s not difficult to use manufacturing steps to make sure that all viable cells are removed, as Dr. Krause himself also notes later in the article, pointing out that the “cells themselves aren’t a real concern, because we are sure that they are all removed.” It really isn’t that difficult.

Of course, that leaves other concerns that are not quite as fantastical as tumors, but still a bit of a stretch. In fact, that the FDA discussed and investigated these possibilities so thoroughly, as demonstrated in its report (linked to in the article and found here as a Scribd document). Krause describes them:

Cell DNA also is a theoretical concern, both because cell DNA could contain infectious genomes — and we know that DNA can be picked up by cells and that then could lead to initiation of an infection — as well as a theoretical oncogenic risk. And then there is the question of adventitious agents.

There are several ways in which tumor derived cells might lead to an increased adventitious agent risk, potentially an increased risk due to more passages in history of the cell, as the cell line was developed. Potential ability of a cell substrate to support the growth of additional viruses, but probably most relevant to the discussion in the potential for a virus to have been involved in tumor development in the first place, because that is one of the differentiating factors of these cells with other cells.

In other words, tumor cell lines really aren’t that different from fetal cell lines already used to make vaccines. The one difference is that they might harbor viruses that originally led to the formation of the cancer from which the cell lines were derived.

It’s important to remember right here that the cell lines that were being considered for use as substrates in which to grow viruses are:

  • A549 cells: A lung cancer cell line. It was derived from a 58 year old Caucasian male with lung cancer associated with smoking. Its dominant mutation has been identified as KRAS. (You don’t need to know the details.)
  • HeLa cells: You’ve probably heard of this cell line before. It was derived from a woman named Henrietta Lacks with cervical cancer back in the 1950s, and its development was the topic of a recent bestseller. It’s one of the oldest established cancer cell lines still in use. Now, cervical cancer is indeed usually caused by human papilloma virus, it’s true. In Lacks’ case, it was HPV type 18. It is known. (Sorry, couldn’t resist.)

Basically, a company called PaxVax has been experimenting with the use of A549 cells as a substrate to grow virus to make vaccines against pandemic influenza, anthrax, and HIV, using various strategies. The primary advantage the company finds is greatly increased yield of virus compared to other methods of growing the virus. For example, the yields gained from A549 cells were 10- to 40-fold higher than they were from MRC-5 cells, one of the fetal cell lines commonly used to grow virus for several vaccines.

Rebecca Sheets, an investigator at the NIH—specifically National Institute of Allergy and Infectious Diseases (NIAID)— then described investigations into the use of HeLa cells as a substrate to develop HIV vaccines. The reasons were similar: High yields. But she also described another potential benefit of using tumor-derived cell lines that might not be so obvious, at least not to lay people. First, however, you have to understand the difference between primary cells and cell lines. Primary cells are cells grown in culture after having been directly isolated from an organism. Human foreskin fibroblasts, isolated from—yes, and yuck—discarded foreskins from circumcisions, are commonly used primary cell lines. The advantages of primary cell lines is that they are more like “normal” than cell lines. The key disadvantage of them, however, is that they only replicated a limited number of times and therefore, as they are passaged in culture they undergo senescence and stop growing. Cell lines, on the other hand, can divide indefinitely. Unfortunately, even cell lines that don’t form tumors have to undergo genetic changes of one sort or the other in order to acquire immortality (the ability to replicate indefinitely without becoming senescent).

Primary cell lines have been used to make vaccines, but they have a huge disadvantage, as you might imagine. That’s why Sheets pointed out that the use of cell lines could actually decrease the risk of infection due to adventitious agents (agents that happen to be in the cells):

And now we are poised to consider tumor-derived cell lines such as the A549 cell line that you heard from PaxVax earlier, and HeLa cells, which I am going to tell you about now. So over time, primary cells, while still in use, have really fallen out of favor because they cannot be banked and well-characterized prior to use in production, and they must be sourced each time. So there is always that risk of introducing an adventitious agent from the primary source. Whereas, cell lines can be banked. They can be thoroughly and exhaustively tested prior to their use in production. And therefore, just the use of a cell bank can lower your risk of adventitious agent contamination.

So what has really driven this evolution? I think in large part we have a much better understanding of cell biology and the molecular basis of cancer than we did 60 years ago. We certainly have better tools to characterize cells and to characterize products. We have a greater experience with the various different cell lines, including a lot of experience from the veterinary field, as well as the biotech therapeutics field that the vaccines, human vaccines field, can trade on.

And that’s a huge difference from 60 years ago. Lunoe, not surprisingly, brings up a favorite bugaboo of antivaccinationists, namely the contamination of polio virus with SV40. I’ve discussed this unfortunate history extensively before. Suffice to say, there’s never been any good evidence that contamination with SV40 caused any cancers, but, more importantly, 60 years ago we had no clue how to detect viruses like SV40 reliably. Today not only can we detect SV40 at extremely low copy numbers, but we can sequence it and tell exactly what its origin was. Moreover, we understand far more about how cancer develops, as Dr. Sheets pointed out:

We know now that tumors arise from genetic changes that result in inappropriate expression or knock out of what started as a proto-oncogene and might get turned into an oncogene. In other words, cancer is in the DNA. Viruses that cause cancer often express proteins that interact with cellular oncoproteins or which are themselves oncoproteins. And so again, it is in the nucleic acid of the virus as well that encodes these oncoproteins. We also know now how to more carefully measure cell residuals in products. For example, how to measure host cell nucleic acids and host cell proteins, which in traditional vaccines were not measured.

We have improved methods for detection of viruses and viral nucleic acids, and we also have improved purification processes to remove or destroy cell residuals in viruses that might have been present. And I should add that we now operate more in an era of current good manufacturing practices, which was not in place in the 1950s and 1960s.

So what about DNA contamination? I’ve discussed in detail why it’s incredibly unlikely that any vaccine would contain sufficient DNA from the cells in which its virus was grown to have a significant effect on the organism to which the vaccine is administered, much less to cause cancer. Indeed, Sheets points out that residual host cell DNA from a vaccine preparation was assessed by PCR for the human papilloma virus that caused the transformation of HeLa, pointing out that the lower limit of detection of the assay was 25 copies per ml. The total cellular DNA measured was approximately 60 picograms (thats 10-12 grams) per dose of vaccine, which is extremely low. In addition, Benzonase® Nuclease is used to digest DNA in the manufacturing process, so that any fragments of the oncogene from HPV are digested to unmeasurable levels.

The FDA even considered the possibility of bovine spongiform encephalopathy (BSE), a disease caused by prions, given that fetal bovine serum or calf serum are commonly used in the cell culture media used to grow the cells. Prions are abnormal pathogenic agents that are transmissible. They cause encephalopathy by inducing abnormal folding of certain normal cellular proteins found most abundantly in the brain. They are the cause of so-called “mad cow disease,” and can therefore be transmitted by consuming beef. It’s a long shot, but the fact that scientists consider the possibility of prion diseases, to the point that they discuss the feasibility of growing these cell lines in serum-free medium, shows just how cautious they are.

When you come right down to it, Lunoe’s strategy is obvious: Cherry pick the most damning parts of the discussion that are only damning when taken out of context, as Lunoe does, all to make it sound as though the scientists and regulators of the FDA and NIH were trying to pull a fast one or were insufficiently concerned about safety in considering the use of A549 or HeLa cells as substrates in which to grow viruses for vaccines, when in fact the totality of the transcript reveals just the opposite: Endless discussion of whether DNA from such vaccines could cause tumors (highly unlikely), complete with even more discussion of tests to make sure that any possible DNA that might conceivably cause a tumor is purged from the final vaccine, up to and including animal carcinogenicity tests, about which, by the way, the scientists also argued about, in particular whether they needed to watch the animals longer to rule out any tumorigenicity. In other words, contrary to the impression given by Lunoe, the entire tone of the hearing was one of hyper-caution, of considering all possibly ways in which harm might be caused by using human tumor cell lines as substrate to grow virus for vaccine.

Not surprisingly, the scientists were worried about whether or not the public would accept vaccines made from human tumor cell lines, and Lunoe made sure to quote these deceptively. For instance, according to Lunoe quoting Marion Gruber, Director of the Office of Vaccines at the FDA:

The minute you describe something in the package insert in terms of potential clinical safety concerns, I think that really precludes using these cell substrates.

From this, she claims that the FDA was plotting to leave the identity of the cells used off the package insert. Now here’s the quote in context:

The quote in context:

I would like add to this — it goes back to the earlier point I made — I think the minute that we think that we have to address any of these concerns in the clinic, we would not be using — we would be very reluctant for a cell substrate such as these cells to be used for vaccine production, if we are not reasonably assured that the characterization done, as we have discussed today, is adequate. The minute you describe something in the package insert in terms of potential clinical safety concerns, I think that really precludes using these cell substrates.

That I don’t think we would really elaborate on in a package insert, because these things should be thoroughly tested and evaluated in establishing the manufacturing process. In our review of the data, we will have to have come to the conclusion that these cells are safe for use for vaccine production.

It’s a rather different implication, don’t you think?

Lunoe then quotes Jim Cook, Director of Infectious Disease at Loyola Medical Center in Chicago, and co-director of the Infectious Disease and Immunology Institute:

When it gets right down to what’s in the vial and what the patient is going to ask me about, whether it’s safe, I’m not going to say, well, you know, HeLa cells kill nude mice.

Wow. Sounds really bad, doesn’t it? Well, not really. Not in context:

I’m not a regulator, so I will say just what I think in reaction to the comment about putting comments in a package insert about tumor cells making tumors in which vaccines were made. I would say, from a personal opinion, that you would have to be very careful about the degrees of separation between where the stuff comes from and what you are putting in the vial that the package insert is describing. It’s not at all related, in a certain sense. I’m not 100 percent convinced that whether or not a cell makes a tumor in a nude mouse has anything to do with the safety of a vaccine that ends up getting made. There are concerns we have. It’s a really interesting intellectual discussion. When it gets right down to what’s in the vial and what the patient is going to ask me about, whether it’s safe, I’m not going to back and say, well, you know, HeLa cells kill nude mice.

It’s not a very good analogy, but think about what we do in terms of making bacterial toxins or preparations related to that. You don’t want to go to somebody and say, “You know, botulinum kills people. It can paralyze you. It’s really dangerous,” or, “Anthrax kills people,” when you are trying to make some kind of an antibody against protective antigen or lethal factor.

The degrees of separation between what is being used to make it and what the product is in the vial have to be considered when you are talking to the lay person, or they are going to get completely confused and refuse to use anything. They do that already. They come in with a PDR. You can imagine how it is trying to tell them what to do.

So I would be very careful about that.

All of this represents a reasonable, measured response to questions about what to put on the package insert, making an analogy to other biological products that are potentially dangerous or were derived using biological techniques that sound scary or just yucky and what is put on their package inserts. The point, of course, is that scientists know that antivaccinationists like the crew at the Orwellian-named VacTruth.org and other sites will do exactly what Sandy Lunoe did: Quote mine, cherry pick, exaggerate dangers, and do everything to make it seem as though scientists are reckless ideologues who don’t care about safety.

People like Sandy Lunoe demonstrate why people like Drs. Gruber and Cook are concerned about what goes on package inserts. They have good reason to be concerned, because they know the Lunoes of the world will do their best to twist anything they say and use fear to convince people that any vaccine made using a cancer cell line is too dangerous.