Cervical cancer vaccine – Gardasil 9 shows long-term effectiveness

One of the myths of the anti-vaccine crowd is that we don’t know anything about the long-term effectiveness of the HPV vaccine. Of course, the vaccine was launched in most of the world in 2008, although there is a large pool of women who received the vaccine during the earlier clinical trials, so it will take time to determine long-term effectiveness. A peer-reviewed article was recently published that confirms the long-term efficacy of the cervical cancer vaccine, Gardasil 9.

Each year, we probably will see new articles published that will continue to confirm the effectiveness of the cervical cancer vaccine years after injection. So far, we see no decrease in effectiveness of the vaccine, providing us with solid evidence that it will provide long-term protection against the dangerous cancer-causing virus, thereby preventing HPV-related cancers.

I know this data will not stop the misinformation and false claims about Gardasil. That won’t stop me from discussing this important research.

HPV and HPV vaccines

I know, I’ve written about this vaccine 100 times – however, this might be your first bit of research into the 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 human papillomavirus (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 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.

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.

Cervical cancer vaccine article

A paper was published in October 2017 that continues to show the long-term effectiveness of the cervical cancer vaccine, Gardasil9. This study, published in The Lancet, of 14,215 women in 18 countries provides additional data that extends the initial phase 3 safety and effectiveness trial of the nine-valent human papilloma virus vaccine, Gardasil 9, that was published in February 2015 in The New England Journal of Medicine.

These results strengthen the hypothesis that Gardasil 9 can prevent 90% of cervical cancers – that’s why I call it the “cervical cancer vaccine.”

Let’s take a look at the results. The over 14,000 women were followed by researchers for up to six years after the first Gardasil 9 vaccinations. The women were examined for efficacy at preventing HPV-related diseases and for production of antibodies against the 9 subtypes. The randomized double-blind efficacy, immunogenicity and safety study involved 105 sites in Austria, Denmark, Germany, Norway and Sweden; Brazil, Chile, Colombia and Peru; Canada, Mexico and the United States; and Hong Kong, Japan, New Zealand, South Korea, Taiwan and Thailand.

Half the women were vaccinated with the four-valent Gardasil and half with the nine-valent Gardasil 9. They were followed via gynecological exams for evidence of infections or disease, and their blood sera were tested for antibody levels against HPV.

Gardasil 9 showed 97.4% effectiveness in preventing infections and disease caused by the five additional HPV genotypes not included in the four-valent Gardasil vaccine. Gardasil 9 vaccination produced similar antibody protection against the four HPV genotypes in Gardasil.

The safety profile of the vaccine, published in 2016 in Pediatrics, did not show any serious adverse effects related to the vaccines. In addition, the authors of that safety study stated that:

Study results did not suggest an association between 9vHPV vaccination and CRPS or POTS; of note, an assessment of the occurrence of CRPS (complex regional pain syndrome) and POTS (postural orthostatic tachycardia syndrome) in HPV vaccine recipients conducted by the European Medicines Agency produced similar conclusions.

The relationship of the cervical cancer vaccine to these two conditions has been pushed by anti-Gardasil radicals for a long time. There has been no evidence to support those claims, and this study provides affirmative evidence of a lack of a causal link.

The conclusion from the The Lancet article was:

The 9vHPV vaccine (Gardasil 9) prevents infection, cytological abnormalities, high-grade lesions, and cervical procedures related to HPV 31, 33, 45, 52, and 58. Both the 9vHPV vaccine and qHPV vaccine (quadrivalent Gardasil) had a similar immunogenicity profile with respect to HPV 6, 11, 16, and 18. Vaccine efficacy was sustained for up to 6 years. The 9vHPV vaccine could potentially provide broader coverage and prevent 90% of cervical cancer cases worldwide.

Merck and the cervical cancer vaccine

One more note. This is a post-marketing study sponsored by Merck, which, of course, manufactures and markets both versions of Gardasil. I’m not naive, I know some of you will immediately dismiss it because Merck was involved. It’s a form of the Big Pharma shill gambit, where evidence is ignored as long as someone can make an accusation of Big Pharma money influencing the results.

If someone is going to assert that results are tainted by funding, then please provide the evidence that there is some unethical behavior. A post-marketing study is very expensive, costing several million dollars or more. Merck cannot do these studies without access to researchers across the world.

Merck’s funding of this type of research will include the cost of recruiting patients, diagnostic tests, and all other direct expenses of the study along with compensation for the time and other expenses for the lead researcher at each site. At least in the USA, funding of this type goes through the research institution, which has itself approved the study through its institutional review board (or ethics committee). The researchers on the publication may, after all expenses are paid, receive a small income, probably a lot less than $10,000.

I’ve said this before – maybe the anti-vaccine forces are willing to sell their morals and ethics for a few thousand dollars. However, they probably shouldn’t reflect their unethical beliefs onto others. Unless there is some real evidence of real malfeasance, most researchers would publish evidence irrespective of whether it helped or hurt the the funding source.

And one more thing. This study was done at 105 sites, which probably included a thousand or more researchers and assistants involved in the collection of data. If there was some suppression of data or other unethical act, are we to assume that all of these people are not going to say a word?

Immediately dismissing research funded by industry can introduce extreme bias into examining research. I have criticized “published” (and subsequently retracted) papers from “researchers” sponsored by anti-vaccine groups. Funding only made up a small part of the critique – most of the criticisms were in the methods, statistical analysis, and other points. We should never dismiss evidence based on an imaginary conspiracy theory about funding – it should only be on the quality of the said study.

The cervical cancer vaccine study is sound. It has a large patient population. It has a strong statistical review of effectiveness and safety. It was peer reviewed and published in one of the most powerful journals in the world. The funding source can be a consideration in determining the validity of the study – it can’t be everything.

Summary

After six years, the 9-valent HPV vaccine, Gardasil 9, is greater than 97% effective in preventing infection by the human papillomavirus. Since HPV is directly responsible for a whole host of dangerous and disfiguring cancers, the HPV vaccine can substantially lower the risk of cancers.

This vaccine can reduce the risk of cervical cancer by over 90% – hence Gardasil should be known as the cervical cancer vaccine. However, it helps prevent a lot of other cancers, so it’s not only that.

There are precious few ways to substantially reduce your risk of cancer. Getting yourself and your children the HPV vaccine is one of your best ways to prevent cancer.

 

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!