Data on adverse events after HPV-vaccination is misleading

Af den 19/10/2014

The Danish Health and Medicines Authority’s most commonly reported adverse events after HPV-vaccination with Gardasil, does not correlate with their public information. They try to neglect the most severe and frequent cases – while they highlight the mild and rare cases.

On our page, HPV Vaccine Info, we have examined which types of adverse events that are being reported in Denmark after HPV-vaccination with Gardasil. We were interested in knowing how the accepted adverse effects from the HPV-vaccine correlated with the actual rate of reporting.

When you look at the list of adverse effects and their rate of reporting, you can only wonder why all the adverse effects that The European Medicines Agency (EMA) classify as rare, basically are the adverse effects that are the most common. Likewise, you can only wonder why all the adverse effects that The Danish Health and Medicines Authority (DHMA) and The Danish Cancer Association (DCA) classify as the most common, are the ones that are the least frequent. If we look at some of the adverse effects that DHMA and DCA proclaim are the most common, then they are for example: Headache, nausea, fever, influenza like symptoms, pain on the injection site and local swelling. For most people these adverse effects seem pretty mild. But among some of the more reported adverse effects are for example: Arthralgia, myalgia, paresthesia, sensory disturbances, disturbances in attention, vision impairment, acute abdominal pain and dyspnea. It seems that DHMA and DCA want to mislead the public when it comes to the most severe and frequent adverse effects.

Underneath is a list of the most commonly reported adverse effects in Denmark. It’s made from DHMA’s Drug Analysis Prints from the 30 of July 2014. There are more than 620 reported unique adverse effects but only the 75 most frequently reported are on this list. The names of the adverse effects are both in Danish and in English.


The orange are the adverse effects that we via EMA are told is the most common vaccine related adverse effects. They are mentioned briefly as headache and injection site pain. If you look at DHMA’s homepage nausea and fever are also mentioned as common, and they have also been marked with an orange X on the list. But if you instead look at DCA’s homepage, Vidunderlivet, headache is not even mentioned as one of the most common adverse effects. Instead they mention influenza like illness that can also be found on DHMA’s list of reported adverse effects, it has therefore been marked with an orange X.

The green is adverse effects from Mercks own product resume that is known vaccine related adverse effects. They comprise of the green as well as the orange. Among these dizziness and syncope are mentioned, but they are adverse effects that we are not informed correctly about in Denmark.

The blue are the adverse effects that EMA inform has been discovered after Gardasil hit the market. In these cases the frequency is not known or they are mentioned as rare. Urticaria is an example of a rare adverse effect according to the EMA. But DHMA has received a staggering 83 reports of that adverse effect. Whether that can be classified as rare is up to your own judgment, but if you compare it the other adverse effects on the list, it is one of the most commonly reported adverse effects.

According to the EMA bronchospasm is a very rare adverse effect. And according to the rate of reports to DHMA it does make a lot of sense, since only 2 people have reported bronchospasm. But if you categorize dyspnea together with bronchospasm, you suddenly have more than 50 reported adverse events in that category, and then it is no longer a very rare averse effect (less than 1 out of 10,000 patients). It seems too easy for the EMA and DHMA to manipulate the figures to fit their own agenda.

Syncope and dizziness have only been recognized as adverse effects after Gardasil entered the market and they have been marked with a blue X. It was just in August 2013 that DHMA in their magazine Nyt om Bivirkninger (News about Adverse Effects) wrote that: “The most commonly reported adverse effects are dizziness, syncope and anaphylactic shock.” It is kind of precarious that DHMA highlights anaphylactic shock, since anaphylactic shock is one of the least common adverse effects with only 8 cases in Denmark. They could have chosen a wide range of more frequent and severe adverse reactions, but it seems that they just went with the adverse effects that were brought to light by Merkc a long time ago. You can only get the feeling that they live by the mantra – nobody will check up on it anyway.

But the question is why most of the frequent adverse effects are not being mentioned by the health authorities or the manufacturer? Even though the list of adverse effects from Denmark is not the full picture but only give us some patterns, who is it exactly that makes and limits the list of potential adverse effects, and are their interests public health or an increase in vaccine sales?

What about if we got access to the same information abroad as we have in Denmark, wouldn’t the tendency be the same? On the page NVIC (National Vaccine Information Center) they had an 2007 article where they mentioned the most commonly reported adverse effects after HPV-vaccination, using the American VAERS database (Vaccine Adverse Event Reporting System). Already at that time the most commonly reported adverse effects were pain, syncope, dizziness, fever, paresthesia, rash, dilated blood vessels, headache and vomiting. Furthermore you can see the same tendency in USA as we have in Denmark when you look at the reported adverse events.

Experts have estimated that only 1-10 % of all adverse events are being reported. If you suspect any sort of adverse effect after a HPV-vaccination, it is very important that you get a doctor to register it or register yourself (if you are a Danish citizen) via: