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Human Papillomaviruses (HPV) are the cause of genital warts, and believed to lead to a number of cancers. But there's a vaccine for HPV that can prevent you from getting infected. This week, Rosianna sends in some questions about the safety and efficacy of the vaccine, based on some emails she's received. Aaron takes the opportunity to talk about HPV, how the vaccine works, how safe it is, and how misinformation is preventing us from saving lives.

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Rosianna: Hey Aaron. So I received the HPV vaccine a couple of years ago. I just got this really scary email from my friends that basically says that the HPV vaccine is killing people, that the lead researcher has spoken out against it and also that it basically does nothing to prevent cervical cancer whatsoever. Can you help because I’m really freaking out about this right now.

Aaron: The HPV vaccine is the subject of this week’s Healthcare Triage.


When I was a medical student interested in becoming a pediatrician, we were warned again and again about a disease called Epiglottitis. It’s just what it sounds like, an infection of the epiglottis, most often by a bacteria known as Haemophilus influenzae type B. It was always an emergency requiring rapid intubation. Kids died from it. But by the early 90’s, the Haemophilus influenzae type B or HIB vaccine was being commonly used. And by the time I was a resident, the incidents of HIB disease had declined by more than 99%. I’ve never seen a case of epiglottitis – ever. Know why? ‘Cause vaccines work and when people attack them I start to get a bit upset. As Rosianna said, there’s an email going around that claims that one of the researchers who was involved in the discovery of the HPV vaccine has now renounced it. That’s not entirely true.

But before we get into that, let’ start with some facts that no-one disputes. Human Papillomaviruses are a group of viruses that are known to cause warts. About forty types of them are transmitted by sexual contact. Any type of sexual contact. About six million new infections occur each year in the United States. That’s a huge number, in fact HPV is so common that almost all women will have an HPV infection at some time in their life. For the vast majority of them this isn’t much more than an inconvenience. Their immune system fights the infection off and they’re fine. But in some women, especially those infected with certain strains of viruses, the infection sticks around. Some of those cases lead to cervical cancer. About 4000 women die of cervical cancer in the United States each year. About 250,000 of them die from it worldwide. The HPV vaccine was originally developed to prevent women from being infected and thus prevent them from getting cervical cancer later. And that’s where we can re-join Rosianna’s story.

Doctor Diane Harper, one of the researchers of the vaccine itself has claimed that the manufacturers of the immunization are overselling its cancer protection properties. She’s not totally wrong. One of her complaints is that you need immunity for a long period of time to make sure the protection lasts. The vaccine hasn’t been around long enough to prove that’s the case. But that’s not a reason not to use it. It’s a reason to monitor its long term potency and give a booster if necessary and we’re doing that.

Her other claim is that since regular pap smears can detect early problems and help with diagnosis leading to significantly reduced cervical cancer mortality, we don’t need a vaccine. She says that pap smears prevent cancer. That’s not true. They help detect it earlier, but cancer still occurs. Moreover, many women don’t get pap smears regularly. They cost money and time and we have pap smears today and like I said thousands of women die of cervical cancer every year.

And cervical cancer isn’t the only cancer that HPV causes. The incidence of rectal cancer has been increasing for decades and most experts believe that HPV is partially the reason for it. The same goes for oral cancers. A recent study found that more than half of such cancers were associated with HPV infections. There are no pap smears for those types of cancer, there’s only the vaccine. And these cancers occur in boys as well as girls. That’s why we’re now recommending that everyone get the vaccine. The only way never to get HPV is never to touch another humans genitals – ever. For most people that’s not gonna happen. Even condoms aren’t totally protective here since you can get HPV from an area of skin that’s not covered. It’s either never ever ever touch or get the vaccine ‘cause the vaccine works. Studies show that.

The vaccine was introduced in late 2006. In the three years before that the prevalence of HPV infection in girls aged 14-19 years was 11.5%. In the three years after it was introduced the prevalence was only 5.1% and that’s with only a third of girls in that age group even getting the vaccine. Know what would have happened if we’d done better? Another 50,000 girls alive today would not get cervical cancer in their lifetimes if we got that number to 80%.

The vaccines are safe too. By last summer, more than 46 million doses of the vaccine had been given in the United States. Initial studies conducted before FDA approval found no serious side effects. A recent safety review by the FDA and the CDC found reports to the vaccine adverse event reporting system had been consistent with those preapproval safety studies. In fact, the CDC has investigated many of the deaths allegedly attributed to the vaccine and found that there’s no consistent pattern and nothing that links them to getting the immunization. The Institute of Medicine did their own review and found, again, no reason for concern.

Some people are opposed to the HPV vaccine because they believe that it sends an implicit signal to girls that the sexual activity through which they might acquire HPV is permissible. In other words, they think that if you give the vaccine to girls it makes them more likely to have sex. Someone should do a study to see if that actually happens. And of course someone has. Researchers looked at 1398 girls of whom 493 got the HPV vaccine and 905 didn’t. Then they looked at the pregnancy rates in those two groups as well as pregnancy testing rates. They even looked at reported contraceptive counselling. You know what they found? There were no significant differences in any of these things between girls who received an HPV vaccine and those who did not.

And why do we need to start the vaccine when girls are young? Because it only works if you’ve never been exposed to HPV before.  The only way to guarantee that is to catch kids before they ever have sex. Research shows that the average age of first intercourse in the US is seventeen for boys and seventeen and a half for girls. But more than 6% of kids in the United States have had sex before the age of thirteen. Look, I think that’s too young too but those are the facts. Moreover, vaginal intercourse isn’t the only type of sex that can give you an HPV infection. An additional 7% of girls and 9% of boys have engaged in oral sex without ever having vaginal intercourse. Bottom line, about half of the almost 19 million new sexually transmitted infections diagnosed each year are in teens and young adults. We need to catch these kids early.

I have one more bit of research for you. The most common reasons that parents refuse the HPV vaccine for their kids are safety concerns and because they think it’s not needed. In other words, they’re getting misinformation from emails and articles like the one that showed up in Rosianna’s inbox. That’s a tragedy and a preventable one. Vaccinate your kids.