Gardasil prevents cancer – evidence for oral cancer protection

According to recent studies from the CDC, only about 63% of teen girls and 50% of teen boys have started the HPV vaccination series. The relatively low vaccine uptake, despite the evidence that Gardasil prevents cancer, one of the few ways to actually prevent cancer, is especially frustrating to those of us who are supporters of the vaccine. However, new data that Gardasil prevents cancer may drive acceptance for the vaccine – new research appears to show that the HPV vaccine may protect against head and neck cancers.

Gardasil 9, the most current version of the vaccine, was approved to protect against cervical, vulvar, vaginal, and anal cancers in females along with anal cancers in males – if it is also shown to prevent oropharyngeal cancers (and eventually gets new indications after FDA review), maybe that can increase the lagging HPV vaccination rates.

All about HPV vaccines

I know, I’ve written about this vaccine 100 times, so you’ve read the following few paragraphs enough times to quote them without looking. Actually, I add information as necessary to make sure you have up-to-date facts and figures about the HPV vaccine.

However, for some of you, this might be your first bit of research into the human papillomavirus (HPV) vaccine, so it’s important to get a brief overview of HPV and the vaccines. If you’ve read this before, just skip to the next section if you want.

Genital and oral  HPV are the most common sexually transmitted infections (STI) in the USA. There are more than 150 strains or subtypes of HPV that can infect humans, although only 40 of these strains are linked to a variety of cancers. HPV is generally transmitted from personal contact during vaginal, anal or oral sex.

Although the early symptoms of HPV infections aren’t serious, those infections are closely linked to many types of cancers in men and women. According to current medical research, here are some of the cancers that are linked to HPV:

These are all dangerous and disfiguring cancers that can be mostly prevented by the HPV cancer vaccine. If you’re a male, and you think that these are mostly female cancers, penile cancer can lead to amputation of your penis. Just think about that guys.

HPV is believed to cause nearly 5% of all new cancers across the world, making it almost as dangerous as tobacco with respect to cancer. According to the CDC, roughly 79 million Americans are infected with HPV–approximately 14 million Americans contract a new HPV every year. Most individuals don’t even know they have the infection until the onset of cancer. About 27,000 HPV-related cancers are diagnosed in the USA every year.

There were two HPV vaccines on the market before 2014. GSK, also known as GlaxoSmithKline manufactured Cervarix, a bivalent vaccine, but it has been withdrawn from the US market, because of the competition from the other HPV vaccines. In Europe and other markets, Gardasil is known as Silgard.

Merck manufactures the other HPV vaccines. Its first vaccine, the quadrivalent Gardasil, targets the two HPV genotypes known to cause about 70% of cervical cancer and two other HPV genotypes that cause genital warts. The newer Gardasil 9, approved by the FDA in 2014, is a 9-valent vaccine. It targets the four HPV genotypes in the quadrivalent version, along with five additional ones that are linked to cervical and other types of cancer. Both versions of Gardasil are prophylactic, meant to be given before females or males become exposed to possible HPV infection through intimate contact.

There are precious few ways to actually prevent cancer – it does not include drinking your favorite whey protein-blueberry-kale-quinoa-seaweed smoothie every day. Quit smoking. Stay out of the sun. Maintain a healthy weight. Quit drinking. And get your HPV vaccine.

(Just a quick note. There are actually two cancer-preventing vaccines. Gardasil is one, and the hepatitis B vaccine, which prevents hepatitis B viral infections. Chronic hepatitis B infections can lead to liver cirrhosis or cancer. Liver cancer is actually one of the few cancers in the USA where the incidence has increased over the past few years. And if you follow the anti-vaccine rhetoric, you know the hepatitis B vaccine is almost as controversial as the HPV vaccine.)

Gardasil prevents cancer – new study

A new study, published in the Journal of Clinical Oncology, suggests that Gardasil may protect against head and neck cancers. It found an 88% reduction in oral infections (which, if they are HPV related, are an important risk factor for these cancers) for those who were vaccinated with Gardasil.

Maura Gillison MD PhD of the MD Anderson Cancer Center in Houston, TX, the lead researcher, and her team analyzed data from the National Health and Nutrition Examination Survey (NHANES). This was a survey conducted by the National Center for Health Statistics designed to assess the health and wellness of the U.S. population. Since 2009, Gillison and her team have worked with NHANES to examine oral HPV infections along with the effect of Gardasil on its incidence.

This study relied upon data from 2011-2014. Participants in the survey self-reported whether they had received one or more HPV vaccines. Her study compared HPV infection rates among those who received a shot of an HPV vaccine and those who did not, out of a group of 2,627 young adults aged 18 to 33.

The researchers observed that the oral infection rates in the vaccinated group were about 88% lower than those individuals who were not vaccinated. Moreover, the investigators actually found no infections in vaccinated males, which would suggest that Gardasil may reduce the prevalence of those infections by as high as 100%. HPV-related head and neck cancers disproportionately affect males, so this data may be important in increasing Gardasil vaccination rates in males.

This research does give us some preliminary evidence that Gardasil is much more effective than originally described, and there’s nothing wrong with that.

Summary

Now, let’s be clear – there is overwhelming evidence that Gardasil prevents cancer, especially cervical, vulvar, vaginal, and anal cancers. Now we have new evidence that Gardasil may prevent head and neck cancers, which are more prevalent amongst males, though still a large risk factor for females.

Again, there are only a handful of ways to actually prevent cancer. Why should you or your children get vaccinated against these cancers? It’s obvious – Gardasil prevents cancer.

Editor’s note – this article was initially published in May 2017. In the meantime, the abstract presented at the American Society of Clinical Oncology meeting has been published as a fully peer-reviewed paper. This updated article reflects that change.

Citations

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!