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SKEPTOID BLOG:MercolaWatch: Mis-information about the Gardasil HPV vaccineby Josh DeWald November 23, 2012
Recently, Joe Mercola published another anti-Gardasil vaccine article, the bulk of which is based on a couple of studies (both by the same researchers) purporting to show that not only is Gardasil not safe, it's not even effective. It appears that he makes some inaccurate claims in the article, and argues well past the actual evidence at hand.
The article jumps right in by discussing scary results from the Vaccine Adverse Event Reporting System (VAERS) related to Gardasil. This should always be seen as a red flag and taken with a grain of salt, because anybody can make a claim to VAERS. Basically if you believe that following the taking of some medication or having a medical procedure, that it caused some reaction that you later had, then you can report to VAERS. It is only after statistical analysis and follow-up that the data is meaningful. And the CDC has in fact done that analysis, and found: ...the vast majority (94%) of adverse events reported to VAERS after receiving this vaccine have not been serious... Link between Gardasil a Cerebral Vasculitis-like symptoms "proven"?He cites studies by "researchers from the University of British Columbia" who, in one study, link Gardasil to Vasculitis and in another perform a systematic review of HPV vaccine trials and conclude that the claims about it are over-inflated. I honestly thought to myself "wow, Mercola managed to find a credible study from a university that finds the claims of Gardasil to not be accurate." However, if you follow through on the sources a bit, you'll find:
After thorough review and discussion of theTomljenovicarticle, the CDC-CISA working group identified substantial methodological concerns and lack of evidence to support the authors’ conclusions that the two patients had vasculitis, that HPV4 vaccine particles were in the brain tissue, or that HPV vaccine was causally associated with death from cerebral vasculitis. Effectiveness of Gardasil HPV vaccine in question?Their other study, "Human Papillomavirus (HPV) Vaccines as an Option for Preventing Cervical Malignancies: (How) Effective and Safe?"isan "Ahead of print" copy from September 2012 for publishing in Current Pharmacological Research, but it's not clear if and when it will appear in the actual journal, so as of now it is not officially published scientific literature. There are currently no citations or responses to it, and I am not qualified to add in my own analysis of that paper. But given that the simple 2-case study was shown to be invalid, it seems wise to at least be wary of a more complex statistical analysis by the same authors. I would however like to quickly discuss a note that Mercola adds about how the documents submitted to the FDA by Merck (manufacturer of Gardasil) that there may actually be increased risk of cervical cancer from taking the vaccine if you have been exposed previously. In this case, he does in fact link to the FDA, but I believe he is speaking past the actual evidence, in that it really is specific to women who have uncleared infections (more reason for early vaccination), and even then the particular group in the study was unbalanced, skewing the numbers. The FDA's analysis on that was (emphasis mine): while the subgroup from study 013 remains a concern of the clinical reviewteam, there is some evidence that this represented an unbalanced subgroup whereGardasil™ recipients at baseline had more risk factors for development of CIN 2/3 orworse. Furthermore, when the subgroups from three studies are combined, these groupsappear to be more similar. Finally, there is compelling evidence that the vaccine lackstherapeutic efficacy among women who have had prior exposure to HPV and have notcleared previous infection (PCR positive and seropositive), which representedapproximately 6% of the overall study populations.If you read the rest of the document, you can see just how truly effective the vaccine is (discussed below as well). Condoms are more effective than vaccination?Mercola continues... First,in more than 90 percent of cases, your immune system can clear HPV infection within two years on its own.Keeping your immune system strong is important.This strikes me as a rather dangerous statement to make, despite it technically being true. It makes HPV sound like it is not a big deal. According to the CDC (emphasis mine), "each year, about 12,000 women get cervical cancer in the U.S. Almost all of these cancers are HPV-associated." So, yes, of the millions of cases of HPV (6 million new cases a year), most go away on their own. But sub-clinical ones, or ones that your body isn't able to fight for some reason or another, can lead to cervical cancer. Mercola again: In addition, HPV infection is spread through sexual contact and research has demonstrated that using condoms can reduce your risk of HPV infection by 70 percent,which is far more effective than the HPV vaccine!Mercola does not cite where he got the information that 70% prevention is "far more effective" than the HPV vaccine, considering that the vaccine has a 94-100%(also here and here)success rate at preventing the cancer-causing versions of HPV (the focus of the vaccine). It's possible he's referring to an 18-40% number that is applicable across all strains of HPV (which are not targeted specifically by the vaccine), but he does not in any acknowledge the larger numbers that are more relevant (Merck and the FDA know that the vaccine is not effective against every single strain of HPV). Not surprisingly, the doctors at Science-Based Medicine have explored the safety and efficacy of the Gardasil HPV vaccine(efficacy links come from them). And of course, the CDC is a great "official" source for information about dangers of HPV and reason for vaccination, while the FDA contains information about the safety of the qHPV vaccine. ConclusionsThe rest of the article on mercola.com discusses "informed consent" and getting involved with legislatures and submitting personal anecdotes to the media and Internet. That's not within the scope of this short entry so I won't comment further on those issues. The FDA and CDC continue to affirm the safety and efficacy of the Gardasil HPV vaccine. The information presented by Mercola does not add anything to the case against the vaccine. One study is apparently invalid, the other is actually unpublished (so not part of the scientific record yet). I have two daughters myself, so this topic is not purely academic to me. My hope is that articles like the one I discussed do not dissuade parents from avoiding ensuring their adolescent children are properly vaccinated to protect against future cervical cancer. And by the time my own daughters are old enough, we should have enough years of the qHPV (possibly even improved) to see lowered cervical cancer rates (it's actually too early to really tell as it can take 15-20 years for the cancer to come about following HPV). REFERENCES
by Josh DeWald @Skeptoid Media, a 501(c)(3) nonprofit |
