Subject: HPV / Gardasil

From: David Burton Thu, Jun 20, 2013 at 6:26 PM
To: Dr. Holly Phillips
Dear Dr. Phillips,

Thank you for your reply!

The key fact which most (maybe all!) news stories have omitted is that the press release about the study discusses only the prevalence of the four HPV types targeted by the vaccine (which they called "vaccine-type HPV"), only two of which are "high-risk" strains (types 16 & 18).

The Markowitz paper is much better than the CDC's misleading press release about it. Look a this graph (Markowitz's figure 1). You can see that, even before the vaccine reduced the incidence of types 16 & 18, most of the high-risk HPV infections were of other types, confirming Winer, 2006.

From that graph, it appears that only about 19% of high-risk HPV infections were types 16 & 18 in 2003–2006, and only about 13% in 2007–2010.

It is frequently claimed (by Merck & by various authors, including
Markowitz) that approximately 70% of cervical cancer cases are caused by types 16 & 18. That suggests that a 50% reduction in 70% of cases would lead to an overall (0.5 x 0.7 = 0.35) = 35% reduction in cervical cancer cases. But that is almost certainly a false hope. It is based on very dubious assumptions:
  1. The study from which the 70% number comes (de Sanjose, et al, 2010) simply looked for the presence or absence of various HPV strains in preserved tissue samples from cervical cancer patients. They found that 71% of those patients were infected with HPV type 16 and/or 18.

    But that does not mean types 16 & 18 caused all those cancers! For one thing, many of those patients were also infected with other high-risk types of HPV, which presumably caused at least some of the cancers. Also, 15% of the cancer patients had no detectable HPV infection at all, which suggests that in a significant percentage of the patients with HPV infections the cancers might also have had other causes.

    So it is statistically incorrect to conclude from de Sanjose et al that 70% of cervical cancer cases are caused by HPV types 16 & 18.

  2. There is evidence that HPV types 16, 18 & 45 may have higher oncogenicity than some other high-risk types, because in women infected with those HPV strains cervical cancer seems to develop at a somewhat younger age. A higher oncogenicity would contribute to the high percentage of current cervical cancer patients infected by those strains of HPV.

    But it almost certainly is not the only reason. The changing relative prevalences of different HPV types may be a more important cause.

    Cervical cancer is typically diagnosed decades after the infection. So the prevalence of various high-risk HPV types decades ago is what largely determines the percentages of today's cancer cases caused by those types. The (different) prevalence of high-risk HPV types today is what will determine the percentages of different types that cause cervical cancer in the future. If types 16 & 18 were relatively more prevalent compared to other high risk types thirty years ago than they are today, then, like mediocre generals, we're building defenses for the previous war, instead of the next.

But the news gets worse. Look at Markowitz's table 3:

Look at the lines labeled "Vaccinated" and compare them with the lines labeled "Unvaccinated."

Do you see it? It is the vaccinated patients who have the highest HPV infection rates!

The overall prevalence of HPV among vaccinated sexually-active teens is 50.0%, but among unvaccinated sexually-active teens it is only 38.6%.

The prevalence of high-risk HPV strains other than 16 & 18 is similarly skewed: 35.2% of vaccinated sexually-active teens are infected, and only 25.3% of unvaccinated sexually-active teens.

Of course, vaccinated teens had much lower rates of type 16 & 18 infection than did unvaccinated teens, but that wasn't enough to offset the vaccinated teens' higher rates of infection with other high-risk types. Because most high-risk HPV infections are other types, a slightly higher percentage of vaccinated teens had high-risk HPV infections than did unvaccinated teens.

Obviously, vaccination does not protect against infection with high-risk strains of HPV!

That also suggests an obvious question: If it is true that "girls who received the vaccine did not begin sexual activity earlier than their unvaccinated peers [and did not] engage in higher risk behavior," then what could explain their higher HPV infection rates?

Additionally, Gardasil has its own risks. The number of deaths and injuries is small compared to the number of patients, but it could eventually be dwarfed by the number of future cancer deaths, if some patients mistakenly believe that vaccination means they needn't get regular exams & pap smears.

Please make sure that, in future CBS reports, you tell viewers that Gardasil cannot reliably protect them from cervical cancer. It will not eradicate that disease, nor even come close. The best we can hope for is a modest reduction in the number of cases, and even that is uncertain.

Over-hyping the potential of Gardasil to combat cervical cancer could end up killing more patients than the vaccine saves.


On Thu, Jun 20, 2013 at 1:16 PM, Dr. Holly Phillips wrote:
Dear David,

Thanks so much for watching the broadcast and CBS. Even though the practice of medicine is my greatest joy, I also very much enjoy my role as a journalist, not just to impart information but to incite spirited discussion as well.

The information I reported on came from the large scale CDC study released yesterday, and published in the Journal of Infectious Diseases. Here's a link to the original article.

One aspect of the data I found particularly interesting was that girls who received the vaccine did not begin sexual activity earlier than their unvaccinated peers, nor did they engage in higher risk behavior. The study did not address compliance with regular gynecological exams and pap smears as they enter adulthood. I do hope that all women continue to do both vigilantly.

All the best,

-----Original Message-----
From: David Burton
To: Dr. Holly Phillips
Sent: Thu, Jun 20, 2013 12:18 pm
Subject: HPV / Gardasil

Dear Dr. Phillips,

I was shocked to hear you interviewed on CBS This Morning about the Gardasil vaccine. You told listeners that this vaccine can "eradicate" the disease, and that people who get the vaccine will never get HPV-caused cancers.

That is wildly inaccurate, and deadly dangerous.

Gardasil protects against only a few strains of HPV. According to a U. Washington study (Winer, et al, 2006, Table 2), most recent HPV infections with "high risk" oncogenic strains of HPV are strains that Gardasil does nothing to protect against.

That study made headlines because, unlike most other studies, they found that condoms somewhat reduce the risk of HPV infection. But the study's most important result never made the headlines.

HPV types 16, 18, 26, 31, 33, 35, 39, 45, 51, 52, 53, 56, 58, 59, 66, 67, 68, 73, and 82 have all been identified as high-risk oncogenic strains, and Gardasil only protects against types 16 and 18. Those two types accounted for just 14 out of 78 high-risk infections detected in the U. Washington study. 82% of the high-risk infections were with HPV strains that Gardasil does not protect against.

The relative prevalence of different HPV strains in the general population varies considerably, both by location and over time, and cervical cancer usually takes a long time to develop. Today's cervical cancer cases result from the HPV types which were prevalent decades ago -- and those are the strains that Gardasil is designed to protect against, not the numerous other high-risk strains which now cause most high-risk HPV infections.

Gardasil is like the Maginot Line: a defense designed for the previous war, but inadequate for the current one.

If, after hearing your report, young women who got the Gardasil vaccine before they became sexually active erroneously think that they are safe from cervical cancer, they may forgo PAP smears, and, paradoxically, be at greater risk of dying from cervical cancer than if they'd never gotten the vaccine at all.

PLEASE tell CBS listeners the truth:
  • Gardasil only protects against 2 of the 19 (so far) known high-risk strains of HPV,
  • The great majority of high-risk HPV infections are with strains that Gardasil does not protect against, and
  • Sexually active women are at risk for cervical cancer and other cancers, and still need to get regular PAP smears, regardless of whether or not they've been vaccinated with Gardasil.
If people believe the myth that Gardasil vaccination prevents all high-risk HPV infections and reliably protects them from cervical cancer, some of them will die as a result.


David A. Burton
Cary, NC
M: 919-244-3316

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