HPV vaccine adverse events – this time, POTS


I make my goal that if you’re going to make some claim that goes against the scientific consensus, then it must be done with high quality evidence, preferably published in a high quality medical or scientific journal. It better be peer reviewed. And it better be good research.

Even if the evidence meets that standard, there is an hierarchy of published evidence from meta- or systematic-reviews at the very top, and junk science published in pseudoscience-pushing websites at the bottom. But there is a range of scientific scholarship, and sometimes, even if an article is published in a top quality journal, the results may be misinterpreted, or even be poorly analyzed.

Case report study about the HPV vaccine

The original HPV quadrivalent vaccine, known as Gardasil (or Silgard in Europe), can prevent infection by human papillomavirus, substantially reducing the risk of these types of cancers. An HPV bivalent vaccine, known as Cervarix, is used in some countries, but only provides protection again two of the subtypes most associated with cervical cancer.

So let’s be clear. All forms of the HPV vaccine prevent cancer, one of the handful of things one can do to actually prevent cancer. But still, the antivaccine cult claims numerous HPV vaccine adverse events that are never supported by real research in real clinical or epidemiological studies.

Recently, there was a report in the journal Vaccine, a genuinely high quality journal that reported a diagnosis of postural orthostatic tachycardia syndrome (POTS, a condition in which a change from the supine position to an upright position causes an abnormally large increase in heart rate, called tachycardia) in 21 out of 35 women who received the HPV vaccine within some unknown time period.

The authors then conclude that:

In a population referred for symptoms of orthostatic intolerance and other symptoms consistent with autonomic dysfunction that began in close temporal association with a quadrivalent HPV vaccination, we identified a 60% prevalence of POTS. Further work is urgently needed to elucidate the potential for a causal link between the vaccine and circulatory abnormalities and to establish targeted treatment options for the affected patients.

Oh no, the HPV vaccine is dangerous!!!!

But maybe not

Let’s start at the type of study and then drill down to the evidence.

  • It’s a case report study. This study represents nothing more than observations, and it doesn’t qualify as real scientific data. It cannot and does not show causality. It cannot and does not show anything. Antivaccine cultists will often pull a case report like this and proclaim some horrible danger, when this this type of report shows nothing of the sort. Journals, really good ones, always publish case reports, because they can be indicators of a potential issue. But one must review the data in context (we’ll get to that), and await further clinical or epidemiological studies. In the vast majority of the time, these case reports amount to nothing.
  • There are no controls. This is the major problem with case reports. In this particular study, 35 women were included in the study, most of whom had just completed heavy exercise. Did they check for POTS in a random group of 35 women who also exercised, but weren’t vaccinated? What if POTS is just a sign of heavy exercise? Hang on, we’ll get to that.
  • Small sample size. This sample size is small, not even statistically viable (especially when the authors didn’t bother to compare it to a control group).
  • Is this even plausible? To even begin to make a claim of correlation or causation, one has to provide some level of plausibility. That is, in what possible way could one HPV vaccine injection cause POTS? I am at a loss as to how a little shot of 4 antigens would somehow cause the very complex set of events that lead to POTS. Real science hasn’t even come to a consensus on what the mechanisms are for POTS, but it may be a result of literally 10-20 factors, and none of them is even slightly related to a vaccine.
  • Back to POTS. POTS is a complex condition where your heart rate increase suddenly when you stand or sit up from lying down. Like I said, it’s caused by numerous factors, such as dehydration. Most of these patients had exercised heavily prior to vaccination, and we can assume they may have been dehydrated. Moreover, POTS is not a condition that arises suddenly, it is a chronic condition that debilitates over time. I am more than skeptical that a patient who was completely healthy 10 minutes ago suddenly comes down with a serious and complex conditions 10 minutes later. At this point I’m wondering if Vaccine peer-reviewers were reading the same data as I was.
  • POTS is common in teenage and young adult females. Again, without the control group, how did the authors even begin to make this diagnosis. Better yet, did they check for POTS prior to the study? No, they didn’t.
  • Diagnosing POTS. This point is one of the worst of this article. Diagnosing this condition is not easy (pdf). It isn’t done in a minute–a definitive diagnosis requires blood tests, including tests for hormonal deficiencies, a specialized tilt table test under controlled conditions, and a few other tests to get a definitive diagnosis. These researchers diagnosed POTS with one test–heart rate, which can be indicative of at least 1000 different medical conditions. This is not how one gets a definitive diagnosis of POTS. Did the researchers even take the time to get a consult from a cardiologist?
  • Comment about the authors. I usually don’t care about the authors, unless they are really bad or really good. These authors seem to have a history of bias against the HPV vaccine. If a huge epidemiological study performed by an unbiased group gave us these results, sure I’d be on board. But this group seems to lack any knowledge of what POTS is, let alone establishing a causal link.


Large, multi-center, long-term studies of the HPV vaccine have never once observed or established any link between the vaccine and POTS. Not once. This new study adds nothing to the research regarding HPV vaccine adverse events – really nothing.

Yes, there was an observation, but as far as I can tell, they could not have possibly diagnosed POTS in these patients. So the premise is completely down the drain. They showed no plausibility, let alone correlation or causation between the HPV vaccine and POTS.

But we know the antivaccine cult will be using this study to establish the dangers of Gardasil. But that’s because they are so desperate that they cherry pick one bad study, trying to make it superior to all the great studies that show the HPV vaccine is safe and effective. The cult loses again on the science.

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The Original Skeptical Raptor
Chief Executive Officer at SkepticalRaptor
Lifetime lover of science, especially biomedical research. Spent years in academics, business development, research, and traveling the world shilling for Big Pharma. I love sports, mostly college basketball and football, hockey, and baseball. I enjoy great food and intelligent conversation. And a delicious morning coffee!